Neurofibromatosis Type 1 and Type 2 Associated Tumours: Current Trends in Diagnosis and Management with a Focus on Novel Medical Therapies

Home , Craniopharyngioma, Glioblastoma, Neurofibromatosis type I, Retinoblastoma

Neurofibromatosis Type 1 and Type 2 Associated Tumours: Current trends in Diagnosis and Management with a focus on Novel Medical Therapies

Simone Lisa Ardern-Holmes MBChB, MSc, FRACP

A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy Faculty of Health Sciences, The University of Sydney February 2018

STATEMENT OF ORIGINALITY

This is to certify that this submission is my own work and that, to the best of my knowledge, it contains no material previously published or written by another person, or material which to a substantial extent has been accepted for the award of any other degree or diploma of the university or other institute of higher learning, except where due acknowledgement has been made in the text.

Simone L. Ardern-Holmes

2 SUMMARY

Neurofibromatosis type 1 (NF1) and Neurofibromatosis type 2 (NF2) are distinct single gene disorders, which share a predisposition to formation of benign nervous system tumours due to loss of tumour suppressor function. Since identification of the genes encoding NF1 and NF2 in the early 1990s, significant progress has been made in understanding the biological processes and molecular pathways underlying tumour formation. As a result, identifying safe and effective medical approaches to treating NF1 and NF2-associated tumours has become a focus of clinical research and patient care in recent years. This thesis presents a comprehensive discussion of the complications of NF1 and NF2 and approaches to treatment, with a focus on key tumours in each condition. The significant functional impact of these disorders in children and young adults is illustrated, demonstrating the need for coordinated care from experienced multidisciplinary teams.

Response of the first Australian patients offered novel medications under careful prospective monitoring for safety and efficacy, is described. The approach to treatment trials including principles of patient selection, rationale for candidate medication choices, and identification of appropriate outcome measures are outlined. Treatment response is assessed utilizing multiple criteria including radiologic response, functional status and patient reported outcomes. Tumours considered include plexiform neurofibromas in NF1, treated with the protein tyrosine kinase inhibitor imatinib, with limited benefit. In NF2, vestibular schwannomas were treated using the vascular endothelial growth factor inhibitor bevacizumab, showing definite benefit in a proportion of patients.

Refinements in the clinical approach to NF-associated tumours are discussed, considering results from this early experience. Optimizing tumour surveillance prior to intervention, identifying the most potent yet tolerable agents for use, determining when medical therapy should be utilized in concert with surgical and other approaches, and establishing ways of stratifying individual risk of disease complications and likelihood of treatment benefit, remain important questions for the future.

3 ACKNOWLEDGEMENTS

I have greatly appreciated the support, advice and cooperation of many individuals over time while conducting the research outlined here, and in preparation of this thesis. My sincere thanks and acknowledgements are extended to the following people, in particular:

Professor Kathryn North, as my primary supervisor, who established the clinical service for children with neurofibromatoses in 1990 at The Children’s Hospital at Westmead. Her vision to improve the care of Australian patients has been key to evolution of the treatment approaches presented here. My collaborations with experts in the field internationally, were facilitated by relationships established in the NF community by Professor North over many years. I have appreciated her advice in all aspects of the conduct of this research and preparation of the thesis.

My associate supervisors, Dr Nigel Clarke for his support and encouragement especially in times of change, Drs Mark Wong and Geoffrey McCowage for their expert oncology advice and patient management, Dr Rachel Skinner for her practical and collegial support in the latter phases of research and thesis preparation.

Other oncologists providing dedicated care for patients with complex NF1 and NF2 including Dr Luciano Dalla Pozza (Sydney), Professor Elizabeth Tovey (Sydney), Dr Simon Troon (Perth), Professor Paul De Souza (Sydney), Professor John Simes (Sydney), Dr Michael Slancar (Queensland) (Chapters 4, 8, 9).

Radiologists Dr Jane Li, Dr Lavier Gomes and Dr Kristina Prelog, for their assistance with interpretation of neuroimaging, especially in assessment of target and off-target radiologic response to bevacizumab in a single patient (JL, LG, Chapter 9).

4 NFTumormetrics staff for assistance with tumour volumetry, under the direction of Dr Gordon Harris, with special thanks for his pro-active approach to international collaboration (Chapters 4, 8, 9).

Members of the medical and surgical communities in Sydney involved in the multidisciplinary care of individuals with complex NF1 and NF2, especially colleagues from the Neurogenetics Clinic, The Children’s Hospital at Westmead, and at other institutions.

Dr Gemma Fisher, for assistance with the literature review on NF2 (Chapter 5) including first draft of selected sections of the manuscript, and for support in obtaining ethics approval to evaluate the experience of NF2 in children at our centre (Chapter 6). Dr Fisher also contributed to extraction of data for children with NF2 from clinical notes (Chapter 6).

Dr Manoj Kanhangad for assistance with application for ethics approval to evaluate spinal neurofibromas in children with NF1 at The Children’s Hospital at Westmead (Chapter 3).

Ms Emma Scanlon (Hearing Australia) for her enthusiastic and accommodating participation in audiology surveillance of NF2 patients from around the country. Ms Rosemary Douglas, Ms Katie O’Brien and others providing audiology services for patients at The Children’s Hospital at Westmead.

Ms Natalie Gabrael and Ms Carleen Fernandez for administrative support, including coordinating visits for interstate NF2 patients, and sendaways for volumetric MRI analysis.

Dr Federica Barzi and Ms Elizabeth Barnes, for advice on study design and data interpretation.

The Children’s Tumour Foundation, Australia for financial support, without which the advances in care for NF1 and NF2 patients described in this thesis

5 would not have been possible. This support funded administrative support for care coordination of complex patients with NF1 and NF2 (2010-2012), acquisition of 3D volumetric imaging data, and a stipend toward my employment during that time.

Each and every patient, and family member, whose experiences have enriched my understanding of the presentation and complications of NF1 and NF2, and the potential for resilience in the face of significant medical challenges.

I greatly valued the opportunity to contribute in working groups of the REiNS International Collaboration, for development of clinical trials recommendations. Advice from REiNs colleagues on management of complex clinical problems arising in the care of our patients has been appreciated.

Finally, and most importantly, I thank my family, particularly my husband Connor, and our two sons Adair and Tierney, with whom I have the greatest pleasure and privilege to share the experience of family life.

6 PRESENTATIONS

Ardern-Holmes, S.L., Wong, M, McCowage G, North, K.N. Novel medical treatment approaches to NF1/NF2 associated tumours. ANZCNS Scientific Meeting Sydney, May 2013 (Oral Presentation)

Ardern-Holmes S.L., Kellie S. Treatment of the Oncologic Complications of NF1 and NF2. International Neurooncology Society Congress, Auckland NZ, Oct 2011 (Oral Presentation)

Ardern-Holmes, S.L., Wong, M., McCowage, G., North, K.N. Avastin (bevacizumab) for target and non-target NF2 tumours: trigeminal and spinal tumours also demonstrate response. (Children’s Tumour Foundation Conference Jackson Hole June 2011, Poster Presentation)

PUBLICATIONS

Ardern-Holmes S.L. and North K.N. Therapeutics for Childhood Neurofibromatosis. Current Treatment Options in Neurology, 13 (6): 2011. (Chapter 2)

Ardern-Holmes S. L., & North, K. N. Treatment for plexiform neurofibromas in patients with NF1. The Lancet Oncology, 2012.

Ardern-Holmes S, Fisher, G, North, K. Neurofibromatosis type 2: presentation, major complications and management, with a focus on the pediatric age group. 2016. (Chapter 5)

Mautner, V.F., Nguyen, R., Ardern-Holmes, S.L., Kluwe, L., Renard, M., Clarke, N., Denayer, E., Valeyrie-Allanore, L., Wolkenstein, P., Legius, E. Imatinib did not induce regression of plexiform neurofibromas in 7 pediatric NF1 patients. Blood e- letter, January 26, 2011.

Lim, S, Ardern-Holmes S, McCowage G and de Souza, P. Systemic therapy in neurofibromatosis type 2. Cancer Treatment Reviews. 40: 857-861, 2014.

7 AUTHOR ATTRIBUTION STATEMENT

Chapter 2 of this thesis is modified from the published manuscript [1], as I wrote drafts of the manuscript.

Chapter 5 is published as [2], as I co-authored drafts of the manuscript.

In addition to the statements above, in cases where I am not the corresponding author of a published item, permission to include the published material has been granted by the corresponding author (eg. Appendices).

Dr Simone Ardern-Holmes, 26 February 2017

As supervisor for the candidature upon which this thesis is based, I can confirm that the authorship attribution statements above are correct.

Professor Kathryn North, 28th February 2017

[1] Ardern-Holmes, S.L. and K.N. North, Therapeutics for childhood neurofibromatosis type 1 and type 2. Curr Treat Options Neurol, 2011. 13(6): p. 529-43.

[2] Ardern-Holmes, S., G. Fisher, and K. North, Neurofibromatosis Type 2: Presentation, Major Complications, and Management, With a Focus on the Pediatric Age Group. J Child Neurol, 2016.

8 ABBREVIATIONS

AAO-HNS American Academy of Otolaryngologists-Head Neck Surgery BAHA bone anchored hearing aid CALM café au lait macules CHW Children’s Hospital at Westmead FDG 18F-2-fluoro-2-deoxy-D-glucose GMcC Dr Geoffrey McCowage L left LFTs liver function tests m months MW Dr Mark Wong MEK mitogen-activated protein kinase kinase enzymes MEK1 and/or MEK2 MEN meninigoma MPNST malignant peripheral nerve sheath tumour mTOR mammalian target of rapamycin NCS nerve conduction studies NF neurofibroma NF1 neurofibromatosis type 1 NF2 neurofibromatosis type 2 ONSM optic nerve sheath meningioma PET positron emission tomography PNF plexiform neurofibroma PRO patient reported outcomes QOL quality of life R right REiNS Response Evaluation in Neurofibromatosis and Schwannomatosis International Collaboration SAH Dr Simone Ardern-Holmes Schw schwannoma SD standard deviation SDS speech discrimination score SE standard error SF36 Australian Short Form 36 quality of life questionnaire SSQ Speech Spatial and Qualities of Hearing Scale SSRI Serotonin Selective Re-uptake Inhibitor STIR short T1 inversion recovery SUVmax maximum standardised uptake value (measured during PET) VS vestibular schwannoma WRS word recognition score y years

9 TABLE OF CONTENTS

STATEMENT OF ORIGINALITY .……………………………………….………….……..2

SUMMARY………………………………………………………….…………….…….3

ACKNOWLEDGEMENTS…………………………………………………………………4

PRESENTATIONS AND PUBLICATIONS……………...………………………………...…7

AUTHOR ATTRIBUTION STATEMENT…………………………………………………...8

ABBREVIATIONS………………………………………………………………………..9

LIST OF TABLES, FIGURES, PANELS, APPENDICES…………………...………………..11

CHAPTER 1 INTRODUCTION………………………………………………………..14

SECTION 1: NEUROFIBROMATOSIS TYPE 1……………………………………….20

CHAPTER 2 NF1 / NF2 THERAPEUTICS REVIEW…………………………………...21

CHAPTER 3 SPINAL PNFS…………………………………………………………34

CHAPTER 4 NOVEL MEDICATION FOR COMPLEX NEUROFIBROMAS IN NF1 ……….58

SECTION 2: NEUROFIBROMATOSIS TYPE 2 (NF2) ...………………………….….79

CHAPTER 5 NF2 WITH A FOCUS ON THE PAEDIATRIC AGE GROUP………….…..…80

CHAPTER 6 NF2 IN CHILDHOOD: EXPERIENCE OF NSW………….………………102

CHAPTER 7 NF2 PATIENTS TREATED WITH BEVACIZUMAB: EPIDEMIOLOGY, FUNCTIONAL STATUS AND QUALITY OF LIFE………………………..122

CHAPTER 8 RESPONSE TO TREATMENT WITH BEVACIZUMAB (AVASTIN) FOR VESTIBULAR SCHWANNOMAS IN NF 2………………………………142

CHAPTER 9 NON-TARGET TUMOUR RESPONSE IN A SINGLE NF2 PATIENT TREATED WITH BEVACIZUMAB (AVASTIN)…………………………………….175

CHAPTER 10 CONCLUSIONS AND FUTURE DIRECTIONS…………………………....194

REFERENCES ………………………………………………………………………199

APPENDICES ……………………………………………………………………....214

10 LIST OF TABLES

TABLE 1.1 DIAGNOSTIC CRITERIA FOR SCHWANNOMATOSIS………………………………………………….16 TABLE 2.1 CURRENT SURVEILLANCE AND TREATMENT OF THE MAJOR MEDICAL COMPLICATIONS ASSOCIATED WITH NF1………………………………………………………………………………..24 TABLE 3.1 CHARACTERISTICS OF CHILDREN WITH SPINAL/PARASPINAL PLEXIFORM NEUROFIBROMAS 37 TABLE 4.1 NF1 PATIENTS WITH COMPLEX PROGRESSIVE PLEXIFORM NEUROFIBROMAS TREATED WITH IMATINIB AT THE CHILDREN’S HOSPITAL AT WESTMEAD……………………………………....63 TABLE 4.2. BASELINE SF36 RESPONSES FOR PATIENT 1 AND 2 COMPARED WITH AUSTRALIAN NORMS AND HOSPITAL COHORT OF FRENCH NF1 PATIENTS……………………………………………..70 TABLE 4.3 ADDITIONAL NF1 PATIENTS WITH COMPLEX SYMPTOMATIC PNFS TREATED AT THE CHILDREN’S HOSPITAL AT WESTMEAD SINCE 2009…………………………………………….73 TABLE 5.1 CLINICAL DIAGNOSTIC CRITERIA FOR NEUROFIBROMATOSIS TYPE 2……………………………81 TABLE 5.2 PRESENTING SYMPTOMS OF NF2 POPULATIONS AND AMONG PAEDIATRIC PATIENTS……..93 TABLE 5.3 RECOMMENDED FOLLOW UP FOR CHILDREN AT RISK OF HAVING NF2………………………..96 TABLE 5.4 RECOMMENDED FOLLOW UP FOR CONFIRMED CASES OF NF2 …………………………………97 TABLE 6.1 CLINICAL CHARACTERISTICS OF AUSTRALIAN CHILDREN WITH NF2 AT PRESENTATION…..104 TABLE 6.2 PRESENTING SYMPTOMS OF NF2 AMONG AUSTRALIAN CHILDREN COMPARED WITH OTHER PUBLISHED POPULATIONS……………………………………………………………………………107 TABLE 6.3 CHARACTERISTICS OF CHILDREN WITH NF2 AT LAST FOLLOW UP, INCLUDING COMPLICATIONS, HEARING AND VISION, AND IMPACT ON COMMUNITY PARTICIPATION 109 TABLE 6.4 INCIDENCE OF NF2 DISEASE COMPLICATIONS DURING CHILDHOOD………………………….112 TABLE 6.5 ACTIVE MANAGEMENT OF DISEASE COMPLICATIONS FOR AUSTRALIAN CHILDREN WITH NF2………………………………………………………………………………………………………114 TABLE 7.1 CLINICAL CHARACTERISTICS AT PRESENTATION/DIAGNOSIS AND GENOTYPE OF NF2 PATIENTS TREATED WITH BEVACIZUMAB………………………………………………………….128 TABLE 7.2 MAJOR COMPLICATIONS OF NF2 IN PATIENTS IDENTIFIED AS CANDIDATES FOR BEVACIZUMAB THERAPY……………………………………………………………………………..130 TABLE 7.3 PREVIOUS MANAGEMENT AND INDICATIONS FOR BEVACIZUMAB TREATMENT…………….132 TABLE 7.4 BASELINE NF2 SYMPTOMS QUESTIONNAIRE SCORES AND LINEAR OVERALL WELLBEING SCORES………………………………………………………………………………………………….133 TABLE 7.5 SSQ RESPONSES FOR NF2 PATIENTS AND OTHER HEARING IMPAIRED POPULATIONS……134 TABLE 7.6A SF36 RESPONSES FOR NF2 PATIENTS…………………………………………………………….136 TABLE 7.6B SF36 RESPONSES FOR AUSTRALIAN NF2 PATIENTS, AND COMPARATIVE POPULATIONS…………………………………………………………………………………………..137 TABLE 8.1 CHARACTERISTICS OF PATIENTS TREATED WITH BEVACIZUMAB……………………………….149 TABLE 8.2 SPEECH DISCRIMINATION SCORES FOR PATIENTS 1-6 OVER TIME DURING TREATMENT, INCLUDING MODEL EFFECT OF INCREASING NUMBER OF ITEMS……………………………..154 TABLE 8.3 AAO-HNS HEARING CLASS PRE- AND POST- TREATMENT WITH BEVACIZUMAB………….155 TABLE 8.4 OVERVIEW OF PATIENT RESPONSES DURING BEVACIZUMAB TREATMENT………………….165 TABLE 8.5 INCIDENCE OF ADVERSE DRUG REACTIONS AND LABORATORY ABNORMALITIES ACCORDING TO CTCAE V4.0………………………………………………………………………………………166 TABLE 9.1 VOLUMES AND GROWTH RATES FOR INTRACRANIAL TUMOURS AT TIME POINTS T0, T1 AND T2………………………………………………………………………………………………………..186 TABLE 9.2 VOLUMES AND GROWTH RATES FOR EXTRACRANIAL TUMOURS AT TIME POINTS T0, T1 AND T2………………………………………………………………………………………………………..188

LIST OF FIGURES

FIGURE 3.1 CASE 1. 11-YEAR OLD CHILD WITH LEFT ABDOMINAL/FLANK PAIN, MRI SHOWING LEFT TRANSFORAMINAL SPINAL NEUROFIBROMA AT T10/T11 WITH ANTERIOR DISPLACEMENT OF THE SPINAL CORD……………………………………………………………………………………..38 FIGURE 3.2 CASE 2. MRI SHOWING NEUROFIBROMA AT T11 WITH SEVERE CORD COMPRESSION AND DISPLACEMENT, IN ANOTHER 11-YEAR OLD CHILD………………………………………………..40 FIGURE 3.3 CASE 3. 10-YEAR-OLD WITH CALM OVER THE LEFT SHOULDER/ARM, LEFT SIDED PARASPINAL PNF WITH AXILLARY AND INTRASPINAL EXTENSION AND CORD COMPRESSION…………………………………………………………………………………………….42 FIGURE 3.4 CASE 4. DIFFUSE HYPERPIGMENTATION OVER THE BACK AND BUTTOCKS EXTENDING OVER THE ANTERIOR HIPS BILATERALLY WITH MIDLINE LOWER BACK PLEXIFORM NEUROFIBROMA IN A 5-YEAR OLD CHILD………………………………………………………………………………….43 FIGURE 3.5 CASE 4. MRI SHOWING PLEXIFORM NEUROFIBROMA OVER THE LUMBOSACRAL SPINE AND BUTTOCKS WITHOUT EXTENSION TO THE SPINAL CANAL………………………………………….44 FIGURE 3.6 CASE 5. MRI CERVICAL SPINE OF A 4-YEAR OLD CHILD SHOWING KYPHOSCOLIOSIS, SPINAL DYSPLASIA AND PLEXIFORM NEURFIBROMA ANTERIOR TO THE SPINAL CORD CAUSING CORD COMPRESSION……………………………………………………………………………………………. 45 FIGURE 3.7 CASE 6. EXTENSIVE PLEXIFORM NEUROFIBROMA SHOWN ON WHOLE BODY MRI IN A 17- YEAR OLD, WITH ENLARGEMENT OF ALL SPINAL NERVE ROOTS; CERVICAL TUMOURS AGED 8 AND 18 YEARS SHOWING PROGRESSION, WITH SPINAL CORD COMPRESSION……………….47 FIGURE 3.8 CASE 7. LEFT PARASAGITTAL PLEXIFORM NEUROFIBROMA WITH KYPHOSCOLIOSIS AND EXPANSION OF THE SPINAL CANAL WITH DURAL ECTASIA, AGED 18 YEARS……………………49 FIGURE 4.1 CORONAL STIR MRI a. WHOLE BODY, b. THORACOLUMBAR SPINE (PATIENT 1); c. AXIAL STIR FACE/NECK, d. CORONAL STIR WHOLE BODY (PATIENT 2)………………………………65 FIGURE 4.2 PLEXIFORM NEUROFIBROMA VOLUMES OVER TIME PRE- AND POST-TREATMENT WITH IMATINIB……………………………………………………………………………………………………67 FIGURE 4.3 NF1 SYMPTOMS QUESTIONNAIRE SCORES OVER TIME ON IMATINIB………………………...68 FIGURE. 4.4 LINEAR OVERALL WELLBEING SCALE SCORES OVER TIME ON IMATINIB………………………68 FIGURE 4.5 SF36 DOMAIN SCORES FOR PHYSICAL AND MENTAL HEALTH OVER TIME DURING TREATMENT WITH IMATINIB…………………………………………………………………………………………….71 FIGURE 5.1 NF2 ASSOCIATED TUMOURS: CERVICAL SPINAL EPENDYMOMA WITH ASSOCIATED SYRINX IN A 14-YEAR OLD……………………………………………………………………………………………85 FIGURE 5.2 CUTANEOUS AND OPHTHALMOLOGIC FINDINGS OF NF1 AND NF2…………………………..87 FIGURE 5.3 OPTIC NERVE SHEATH MENINGIOMA IN A 7-YEAR OLD WITH NF2, AND OPTIC PATHWAY GLIOMA IN A 10-YEAR OLD WITH NF1………………………………………………………………89 FIGURE 8.1 MRIS SHOWING VESTIBULAR SCHWANNOMAS AND OTHER TUMOURS FOLLOWED WITH 3D VOLUMETRIC ANALYSIS DURING TREATMENT WITH BEVACIZUMAB……………………………150 FIGURE 8.2 OVERVIEW OF PATIENT TREATMENT WITH BEVACIZUMAB INCLUDING BREAKS IN THERAPY………………………………………………………………………………………………….153 FIGURE 8.3 PURE TONE AVERAGES OVER TIME PRE- AND POST-BEVACIZUMAB TREATMENT…………..156 FIGURE 8.4 VESTIBULAR SCHWANNOMA VOLUMES OVER TIME DURING BEVACIZUMAB TREATMENT..158 FIGURE 8.5 NON-VESTIBULAR TUMOUR VOLUMES OVER TIME DURING BEVACIZUMAB TREATMENT…159 FIGURE 8.6 NF2 SYMPTOMS QUESTIONNAIRE SCORES OVER TIME ON BEVACIZUMAB TREATMENT..160 FIGURE 8.7 LINEAR OVERALL WELLBEING SCALE (LOWS) SCORES OVER TIME ON BEVACIZUMAB….162 FIGURE 8.8 SSQ SCORES FOR EACH DOMAIN OVER TIME DURING BEVACIZUMAB TREATMENT……….163

12 FIGURE 8.9 SF36 DOMAIN SCORES OVER TIME DURING BEVACIZUMAB TREATMENT……………………164 FIGURE 9.1 MRI SHOWING INTRACRANIAL TARGET LESIONS PRE- AND POST-TREATMENT…………….178 FIGURE 9.2 CERVICAL SPINAL TUMOURS PRE- AND POST-TREATMENT WITH BEVACIZUMAB…………..181 FIGURE 9.3 CERVICAL SPINAL TUMOUR (C2/3) ON MRI PRE-TREATMENT AND SHOWING TUMOUR SHRINKAGE POST-TREATMENT……………………………………………………………………….182 FIGURE 9.4 EXTRACRANIAL LESIONS ON MRI FOR PATIENT TREATED WITH BEVACIZUMAB……………183 FIGURE 9.5 LARGE RIGHT AXILLARY SCHWANNOMA SHOWN ON CORONAL MRI…………………………184 FIGURE 9.6 GROWTH RATES OF INTRACRANIAL TUMOURS AT BASELINE AND WITH BEVACIZUMAB TREATMENT………………………………………………………………………………………………187 FIGURE 9.7. GROWTH RATES OF SPINAL AND PARASPINAL TUMOURS AT BASELINE AND WITH BEVACIZUMAB TREATMENT……...... 189

LIST OF PANELS

PANEL 3.1 SPINAL/PARASPINAL NEUROFIBROMAS: CHARACTERISTIC FEATURES AND PRINCIPLES OF MANAGEMENT…………………………………………………………………………………………….36

APPENDICES

APPENDIX 1. NEUROIMAGING OF TUMOURS IN PATIENTS WITH NEUROFIBROMATOSIS TYPE 1 AND TYPE 2: BACKGROUND AND RECOMMENDED PROTOCOLS……………………………………………214 APPENDIX 2. ADDITIONAL PROTOCOL PATIENT SELECTION, TREATMENT AND ADVERSE MONITORING DETAILS FOR IMATINIB TREATMENT OF PLEXIFORM NEUROFIBROMAS IN NF1…………….223 APPENDIX 3. NF1 SYMPTOMS QUESTIONNAIRE………………………………………………………………..225 APPENDIX 4. MEDICAL OUTCOMES STUDY 36-ITEM SHORT FORM (SF36) QUESTIONNAIRE………..228 APPENDIX 5. ADVERSE EFFECTS/TOXICITY OF IMATINIB………………………………………………………..231 APPENDIX 6. NF2 SYMPTOMS QUESTIONNAIRE………………………………………………………………..232 APPENDIX 7. SPEECH, SPATIAL AND QUALITIES OF HEARING SCALE………………………………………..235 APPENDIX 8. ADVERSE EFFECTS/TOXICITY OF BEVACIZUMAB…………………………………………………248 APPENDIX 9. BEVACIZUMAB FUNDING DETAILS………………………………………………………………….249 APPENDIX 10. PUBLISHED PAPERS…………………………………………………………………………………250

13 CHAPTER 1. INTRODUCTION

The neurofibromatoses are genetic disorders, with an incidence of approximately 1:3000 in neurofibromatosis type 1 (NF1) (1-3), and a lower incidence of about 1:30,000 in neurofibromatosis type 2 (NF2) and schwannomatosis (4-7). NF1 and NF2 have been particularly well characterized. However, general knowledge about the rarer conditions NF2 and schwannomatosis outside specialist centres is limited, a problem magnified in the paediatric population.

NF1, NF2, and schwannomatosis-associated tumour suppressor genes (SMARCB1 and LZTR1) cause central and peripheral nervous system tumours to form secondary to dysfunction of molecular pathways controlling cell growth, proliferation and survival (5, 6, 8). Although the neurofibromatoses are typically associated with histologically benign tumours, the potential impact on every aspect of neurologic functioning, requires these tumours to be considered “biologically malignant”. Historically, NF- associated tumours have been difficult to treat, resulting in significant morbidity, and risk of early mortality (8).

Key features of NF1 and NF2, and approaches to treatment of the associated tumours, are the subject of this thesis and will be introduced here, then discussed in detail in subsequent chapters. The hallmark tumours are plexiform neurofibromas (PNF) in NF1, and vestibular schwannomas (VS), which are typically bilateral in NF2. Schwannomatosis, has important clinical and molecular overlap with NF2, and will be briefly described below for completeness, then not further considered here.

Regarding NF1 and NF2, although the literature contains descriptions dating back hundreds of years (to 1761 for NF1 and 1822 for NF2; reviewed in (9, 10)), the differentiation between these disorders was poorly defined over many years, leading to a lack of clarity in the understanding of disease manifestations and natural history until the late 1980s. Establishment of clinical diagnostic criteria distinguishing the two disorders in 1988 was an important historical milestone, adding much needed clarity (11). Furthermore, in 1990 and 1993, the genes encoding NF1 and NF2 respectively were found on chromosomes 17 (12, 13) and 22 (14, 15). Identification

14 of their respective proteins, neurofibromin encoded by the NF1 gene (16), and schwannomin (also known as merlin) encoded by the NF2 gene (17) followed soon after. These advances opened new avenues for establishing disease mechanisms, and exploring disease-specific therapies. Since that time the scientific, medical and patient communities have worked passionately towards understanding all aspects of the biology of NF1 and NF2.

Regarding schwannomatosis, distinct diagnostic criteria have been developed over the past 15 years, using both clinical and molecular features (Table 1.1; (7, 18-20)). Multiple schwannomas (or less frequently meningiomas) occur, in the absence of bilateral vestibular schwannomas, and only rare occurrence of a unilateral vestibular schwannoma. Peripheral nerve schwannomas are relatively more common in schwannomatosis compared with NF2, whereas other tumours such as ependymomas, intradermal skin tumours, skin plaques and ocular manifestations of NF2 are not seen in schwannomatosis. Features of schwannomatosis and NF2 have recently been compared and contrasted with reference to existing literature describing both conditions (18). Chronic pain is often a predominant symptom of schwannomatosis (7).

Concomitant mutational inactivation in 2 or more tumour suppressor genes is required to cause schwannomatosis. Most frequently, mutations of SMARCB1 or LZTR1 (both located on chromosome 22q, along with the NF2 gene) occur de novo, or may act in an autosomal dominant fashion in familial disease. Germline mutations in these genes have recently been identified in 86% of familial and 40% of sporadic schwannomatosis patients respectively (18). Furthermore, somatic mutations of the NF2 gene occur in many tumours from schwannomatosis patients. Pathologic and molecular analysis of multiple tumours may be required to clarify the diagnosis. Clinical and molecular exclusion criteria are also observed, such that schwannomatosis would not be diagnosed in the presence of a first degree relative with NF2, a germline NF2 mutation, or in a patient having schwannomas only in a region previously treated with radiation therapy (Table 1.1;(18)). While there are important overlaps between these distinct conditions, optimal surveillance and treatment will be disease-specific and dependent on accurate diagnosis.

15 Table 1.1 Diagnostic criteria for schwannomatosis

Clinical Diagnosis

≥ 2 non-intradermal schwannomas, one pathologically confirmed and absence of bilateral vestibular schwannomas by high resolution MRI*

One pathologically confirmed schwannoma or intracranial meningioma and an affected first-degree relative with schwannomatosis

Combined Molecular and Clinical Diagnosis Molecular Clinical

≥2 tumours with 22q loss of heterozygosity + 2 pathologically confirmed and 2 different somatic NF2 mutations schwannomas or meningiomas

Germline SMARCB1 or LZRT1 pathogenic mutations + One pathologically confirmed schwannoma or meningioma

Exclusion Criteria

Schwannomas occur exclusively in a region of previous radiation therapy First-degree relative with NF2 Germline pathogenic NF2 mutation

*≤3mm slices through internal auditory canals; some mosaic NF2 patients may be included using these criteria at a young age; schwannomatosis patients may rarely have unilateral vestibular schannomas or multiple meningiomas. Modified from (18).

16 EVOLVING CLINICAL KNOWLEDGE AND TREATMENT APPROACHES FOR NF1 AND NF2 Fortunately, the early 21st century has been marked by advances in research and clinical practice holding real promise for changing the outcomes of individuals affected by NF1 and NF2-associated tumours (8, 21). At the clinical front-line, physicians and surgeons have continued to observe and describe patterns of disease and natural history. Together with the scientific community, an understanding of important factors contributing to tumour development and growth, have been established. Core tumours and their complications have been identified as targets for treatment, directing the development and application of specific therapies (22-24). In addition, approaches to patient selection and outcome monitoring have been refined to optimise critical evaluation of new therapies in clinical trials (25). These efforts have been focused on translating the most effective interventions into routine clinic care as rapidly as possible.

This thesis provides a commentary on these recent developments from a clinician’s perspective, describing experience in tumour surveillance and management at The Children’s Hospital at Westmead, together with collaboration from other centres around Australia.

The thesis is divided into two sections, considering issues relevant to patients with NF1 (Part 1), and NF2 (Part 2). For each condition, an overview of presentation, diagnosis, major complications, treatment challenges and evolving therapeutic approaches is provided, with particular reference to paediatric management (Chapter 2: NF1; Chapter 5: NF2). A case series is also included in each section. For NF1, the presentation and treatment of tumours in and adjacent to the spinal canal is addressed in selected cases, outlining key clinical features to facilitate early diagnosis, surveillance for complications, and guidelines for management (Chapter 3). For NF2, a chapter is dedicated to describing the population of children managed at our centre over a 22-year period, highlighting differences in the paediatric presentation, and severity of disease. The multidisciplinary approach required to address the heterogeneity and complexity of associated clinical complications in childhood is illustrated (Chapter 6).

17 Subsequent chapters in each section describe a critical approach to treatment of target tumours using novel medications. The rationale for selection of each agent as a candidate at the time of this study, and principles guiding selection of patients are outlined in each chapter. Specific outcome measures appropriate for each tumour are described, and results reported. A multi-dimensional approach attempts to document effects on both radiologic features as well as functional outcomes, emphasizing the patient’s experience of disease and treatment.

Chapter 4 describes the first Australian NF1 patients treated with a “biologically targeted” therapy, imatinib mesylate, for plexiform neurofibromas. These congenital onset tumours are one of the most common causes of significant morbidity in NF1 (26, 27), and can be extensive and diffusely infiltrative, occurring in any location with variable clinical consequences. Childhood is typically a time of active growth, and hence a focus for intervention (28). Developing approaches to the radiologic surveillance and measurement of these complex tumours has been critical to assessment of treatment response, alongside selection and measurement of appropriate clinically relevant patient outcomes. Agents such as anti-angiogenic agents, anti- fibrinolytics, farnesyltransferase and mammalian target of rapamycin (mTOR) inhibitors have been considered as candidate medications in early efforts, with limited success (29-32). The tyrosine kinase inhibitor imatinib mesylate demonstrated extremely promising results in pre-clinical and animal studies, and has an acceptable safety profile for treatment of a “benign tumour” (33), and hence has become a priority for Phase 2 clinical trials.

In NF2, vestibular schwannoma (occurring in 95% of patients) has been the primary tumour of interest for medical treatment trials. Similarly, a number of medications have been considered as potential candidates, including other tyrosine kinase inhibitors erlotinib (34, 35) and lapatinib (36), which act on the epidermal growth factor receptor, and have some demonstrated disease activity. Inhibition of angiogenesis using bevacizumab, a monoclonal IgG1 antibody that binds to and inhibits the action of vascular endothelial growth factor-A (VEGF-A), met with particular success in a small group of patients early on (37). These results provided the impetus to assess response carefully in additional patients using VEGF inhibitors, including the first NF2 patients in Australia for whom medical therapy has been

18 offered, as described here (Chapter 8). In preparation for treatment of Australian patients with NF2, assessment of functional status and quality of life at baseline was considered an important complement to established outcomes of hearing function and radiologic response (Chapter 7). Alongside vestibular schwannomas, observations have also been made with reference to meningiomas as secondary targets in NF2 (Chapter 8, Chapter 9). In addition, the “off-target” effects on multiple tumours are presented in a sub-study for a single NF2 patient (Chapter 9), reflecting the extensive tumour burden seen in many patients, and the potential for systemic therapy to benefit separate tumours concurrently.

Finally, in Chapter 10, I highlight future directions in research and clinical care for patients with NF1- and NF2-associated tumours.

SECTION 1:

NEUROFIBROMATOSIS TYPE 1

20 CHAPTER 2. OVERVIEW OF NEUROFIBROMATOSIS TYPE 1: DIAGNOSIS,

MAJOR COMPLICATIONS AND MANAGEMENT IN CHILDHOOD.

Introduction Neurofibromatosis type 1 is caused by mutations in the large NF1 gene located on chromosome 17q11.2, encoding the protein neurofibromin. Neurofibromin is known to act as a tumor suppressor via Ras-GTPase activation, which causes downregulation of cellular signalling by the Ras/mitogen-activated protein kinase (MAPK) pathway. In individuals with NF1 and nonfunctional neurofibromin, Ras signalling is increased, promoting cellular growth, proliferation, and differentiation leading to tumor formation and other manifestations of disease, including deficits in hippocampal learning(5, 38). Neurofibromin is likely to have additional functions; for example, loss of normal GABA-mediated inhibition has recently been shown to contribute to corticostriatal dysfunction associated with working memory deficits in NF1 (39).

NF1 is a multi-system disorder with diverse clinical manifestations(40). The earliest signs of NF1 are cutaneous, including café au lait macules (CALM) and skin fold freckling. Cognitive impairment, optic pathway gliomas, plexiform neurofibromas, and orthopaedic issues constitute the most common and important clinical problems, affecting variable numbers of patients, with a range of severity. Malignant peripheral nerve sheath tumours (MPNST) may arise in pre-existing plexiform neurofibromas at any age, and portend a poor prognosis(41, 42). MPNST together with gliomas contribute significantly to reduced life expectancy for individuals with NF1(43, 44).

The clinical diagnostic features of NF1, along with genetics, disease complications and approaches to treatment are reviewed here.

Diagnosis Clinical diagnostic criteria for NF1 were established in 1987 and are satisfied when

21 two of the following conditions are met (40): • Café au lait macules (six or more larger than 5 mm before puberty or 15 mm after puberty) • Skin-fold freckling (axillae, groin, neck) • Two or more neurofibromas or one or more plexiform neurofibromas • Optic pathway glioma • Two or more iris Lisch nodules • Characteristic skeletal dysplasia (sphenoid wing) • Pseudoarthrosis of the long bones • Presence of a positive family history of NF1 affecting a first-degree relative.

Young children typically present with multiple café au lait macules in isolation, with other signs of NF1 occurring over time (45, 46). Macrocephaly affects about 45% of children and progressive head growth may occur over the first 1 or 2 years. A low threshold for neuroimaging is appropriate, given an increased incidence of intracranial tumors. However, surveillance imaging in the absence of focal neurologic deficit or signs of increased intracranial pressure is not recommended. Optic pathway gliomas are more common in children less than 8 years of age and can occur during infancy. Plexiform neurofibromas are mostly present from birth and become more obvious over the first few years of life. Skin-fold freckling is typically seen from about 3 years of age, whereas Lisch nodules may appear in middle childhood and cutaneous neurofibromas more frequently occur in adolescence and adulthood.

Genetic Testing for NF1 NF1 is inherited in an autosomal dominant fashion with sporadic mutations occurring in about 50% of patients, and a 50% chance of transmission from affected individuals during each pregnancy. A mutation is detected in about 95% of individuals who meet the NIH NF1 diagnostic criteria(47). If clinical criteria for NF1 are met, genetic testing is not considered mandatory in all centres; the 5% false negative rate necessitates annual clinical follow-up of all children with suspected NF1 to detect potential complications. Furthermore, among the many pathologic mutations identified in the NF1 gene, there are few specific genotype-phenotype correlations.

22 Deletion of the entire NF1 gene results in a more severe phenotype (48), associated with facial dysmorphism, increased predisposition for MPNST, cardiac abnormalities, and overgrowth. A 3-bp in-frame deletion in exon 17 of the NF1 gene is associated with a milder phenotype, which does not occur with cutaneous or plexiform neurofibromas (49). Missense mutations in codon 1809 also occur with a recognizable phenotype including presence of CALM, with or without skin fold freckling and iris lisch nodules, and without cutaneous neurofibromas or externally visible plexiform neurofibromas. These individuals also more often have Noonan Syndrome features, short stature, pulmonary stenosis, and learning difficulties (50). Genetic testing has an important role in the context of prenatal testing and pre-implantation genetic diagnosis, though its prognostic value is limited by the variable expressivity characteristic of most NF1 mutations. Segmental neurofibromatosis and somatic mosaicism in both NF1 and NF2 carries a lower recurrence risk (51).

The major differential diagnosis of NF1 is Legius syndrome (also known as neurofibromatosis type-1 like syndrome), an autosomal dominant disorder due to mutations in the SPRED1 gene, which is also involved in the RasMAPK pathway (52). Legius syndrome is characterized by café au lait spots and skinfold freckling, as well as an increased frequency of learning difficulties, but importantly, patients do not develop neurofibromas, OPGs, Lisch nodules, or bone lesions. Of patients positive for a SPRED1 mutation, 48% fulfil NF1 diagnostic criteria based on café au lait spots, freckling, and/or a positive family history of a parent with skin manifestations. It is estimated that 2% of individuals with a clinical diagnosis of NF1 have Legius syndrome; the estimated frequency is 1 in 120,000. At present, genetic screening for Legius syndrome is likely to be most useful in families with autosomal dominant café au lait spots (with or without freckling) without a mutation in the NF1 gene (52).

Complications A recommended surveillance and treatment approach for important complications is shown in Table 2.1. The most frequent neurologic complication in childhood is cognitive dysfunction (53). There is a “shift to the left” in intellectual functioning: the mean IQ for patients with NF1 is in the low 90s, and intellectual impairment (IQ <70) occurs in about 6% of patients.

Table 2.1a Current surveillance and treatment of the major medical complications associated with NF1 Complications Surveillance Treatment Cognitive impairment Developmental screening during preschool years Early intervention by multi-disciplinary team

Autistic Spectrum Disorder Developmental screening during preschool years Specialist intervention/educational support ADHD Screening at intervals during childhood (e.g., at school entry) Stimulant medication Learning difficulties Psychologist assessment during early school years (baseline) Individually tailored educational support; and when specific learning difficulty identified candidate for medication in clinical trial Speech/language disorder Speech evaluation Speech therapy Optic pathway glioma (OPG) Annual ophthalmology evaluation until 8 years of age, every – 2 years ages 8–18; cranial MRI for suspected OPG. For known OPG, quarterly ophthalmology evaluation for 1 Chemotherapy using vincristine and carboplatin year, every 6 months for 1 year, then annually until 8 years if clinically indicated for symptomatic or of age; if older than 8 years, for 3 further years progressing tumor Plexiform neurofibroma Annual clinical examination to identify and monitor growth; Surgical debulking for progressive, symptomatic MRI every 6–12 months for progressive lesions tumors; candidate for medication in clinical trial; analgesia when indicated Malignant peripheral nerve Urgent clinical examination for increasing plexiform Wide surgical excision; consider chemotherapy sheath tumor neurofibroma size, pain, or neurologic dysfunction; MRI, PET, and radiotherapy;candidate for medication in biopsy of affected body region clinical trial Long bone pseudoarthrosis Annual clinical evaluation (infants); x-ray in the event of limb Referral to experienced orthopaedic surgeon; deformity bracing, surgical intervention, and/or bisphosphonates Scoliosis Annual clinical evaluation throughout childhood; x-ray in the Referral to experienced orthopaedic surgeon; event of abnormal spinal curvature surgical intervention if clinically indicated

24 Table 2.1b Current surveillance and treatment of the major medical complications associated with neurofibromatosis type 1

Complications Surveillance Treatment

Hypertension Annual blood pressure monitoring Renal physician referral

For known hypertension,

plasma metanephrines (to detect phaeochromocytoma)*,

renal ultrasound with doppler studies (renal artery stenosis)

Heart murmur Careful annual examination Echocardiogram; referral to cardiologist

Anxiety/mood disorder Annual clinical evaluation Referral to psychologist or psychiatrist

ADHD=attention deficit hyperactivity disorder; *testing not routinely performed in NF clinics for normotensive, asymptomatic patients.

Academic learning difficulties are common in NF1: about 50% of children with NF1 perform poorly on tasks of reading, spelling, and mathematics, and specific learning disabilities (as defined by IQ–achievement discrepancies) are present in 20% of patients. Between 38% and 49% of children with NF1 fulfil the diagnostic criteria for attention deficit-hyperactivity disorder (ADHD) (53, 54). Careful screening, supportive measures in pre-academic environments, and individually tailored educational programs are thus needed.

The neurobiologic basis of cognitive dysfunction and learning disabilities in NF1 is not fully understood, although increased total brain volume and corpus callosum volume, cerebral asymmetries, and differences in grey and white matter have been described in affected individuals. Though T2 hyperintensities are commonly seen in childhood, these decrease with increasing age and are of uncertain significance. However, the presence of discrete thalamic T2 hyperintensities has been associated with severe and generalized cognitive dysfunction (55). Speech and language disorders have been estimated to affect 18% to 58% of school-aged children and adolescents with NF1 (53, 56) and 68% of preschoolers (57). Children with NF1 often have mild generalized hypotonia in association with less well-developed gross motor skills than their unaffected peers, causing minimal functional impairment.

ADHD in the NF1 population is amenable to treatment with stimulant medication (as in other children with ADHD), although data on efficacy are limited (54). Studies of cognitive functioning in the NF1 mouse model have suggested that attention and visual spatial learning deficits (hippocampal-based learning) are due to Ras activation. The cholesterol-lowering agent lovastatin, which inhibits GTPases including Ras, reverses these deficits in the NF1 mouse model (58). Unfortunately, a well-designed clinical trial of lovastatin in children has now shown no significant effect of treatment on attention or visual spatial learning (59).

Optic pathway glioma (OPG) affects 15% to 20% of children with NF1 (60), most before 8 years of age, with about half becoming symptomatic (61). Symptoms and signs include strabismus, proptosis, visual impairment, optic disk pallor, and precocious puberty.

26 Current surveillance recommendations are for an annual general examination to monitor growth and pubertal status, and an annual ophthalmologic evaluation up to the age of 8 years, followed by an examination every 2 years until 18 years of age (60). All children with a suspected diagnosis of OPG should undergo cranial MRI. From the time of diagnosis, monitoring to detect progressive disease rests with regular skilled pediatric ophthalmology assessment together with repeat MRIs. Ophthalmology evaluations are recommended every 3 months for the first year, followed by assessments every 6 months for 2 years, and then annual assessments. Optimal intervals for MRI surveillance have not yet been established, and different centers screen at intervals between 3 and 6 months in the first year. Ocular coherence tomography measures retinal nerve fibre layer thickness, which may be helpful as an adjunctive measurement for assessing progression in the future (62).

Primary treatment for OPG is with chemotherapy, usually a combination of vincristine and carboplatin. There are no definitive evidence-based criteria to guide decisions about commencing chemotherapy. A retrospective multicenter study of 10 major international NF1 centers recently reviewed indications for commencing chemotherapy, demonstrating practice variation among institutions, and visual deterioration in 28% of treated children (63). Prospective studies using novel agents are ongoing.

Other intracranial tumors (typically low-grade gliomas) are less common and tend to have a more favorable prognosis than in non-NF1 patients (64).

Cutaneous and subcutaneous neurofibromas can itch and cause localized discomfort. The significant cosmetic deformity attendant on multiple lesions typically occurs in adulthood; surgical removal is the main intervention, along with laser treatment for small cutaneous neurofibromas.

Plexiform neurofibromas are more complex lesions, thought to be congenital (65). A recent MRI surveillance study identified plexiform neurofibromas in 57% of 65 children aged between 1.7 and 17.6 years, similar to estimates in adults. Of the children with plexiform neurofibromas, 46% experienced pain or neurologic or motor

27 difficulties, usually associated with larger tumors (66). Symptoms associated with tracheal compression may be life threatening.

A recent study of children aged 6-18 years demonstrated pain impacted significantly on daily functioning and quality of life despite pharmacologic management (67). This study identified anxiety and depressive symptoms as contributing factors in reduced quality of life, indicating the need for non-pharmacologic approaches to treatment in a biopsychosocial model of care.

The treatment of complicated plexiform neurofibromas remains a challenge. Symptomatic lesions may be amenable to surgical debulking, but complete resection may not be possible because of the invasive nature of these tumors, and regrowth is common. The goal of surveillance is to identify and treat actively growing symptomatic lesions during early childhood to limit disease progression. Three- dimensional MRI has been shown to be more sensitive than two-dimensional measurements for assessing growth, but it is not available in all centers (28). A number of novel molecularly targeted agents have been assessed in recent trials or are currently being investigated. This includes inhibitors of the c-kit receptor (eg. imatinib) (68), mammalian target of rapamycin (mTOR) inhibitors (eg. sirolimus/everolimus) (69), and MEK inhibitors (eg. selumetinib) (70).

Patients with NF1, particularly those with a high plexiform neurofibroma tumor burden, have a significantly increased risk of malignant peripheral nerve sheath tumor (MPNST), with a lifetime risk of 8% to 13% (41); this represents the major threat of early mortality. Although sarcomatous change can occur at any age, in the paediatric population, MPNST occurs most frequently in adolescence (71). Whole-body MRI surveillance during childhood may help to stratify patients into two groups: those requiring infrequent ongoing scanning and those at risk of complications from existing plexiform neurofibromas, including the risk of transformation to MPNST. However, there is currently a paucity of evidence regarding the utility of MR surveillance in children with asymptomatic lesions. Prospective studies are needed to evaluate the effectiveness of such surveillance.

28 A rapid increase in plexiform neurofibroma growth, increasing pain, and new focal neurologic deficits or other regional symptoms and signs should prompt investigation with MRI (72) and 18F-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography PET/CT studies to detect increased glucose metabolism (73, 74). MPNST confirmed on biopsy is treated with wide surgical excision and adjuvant therapy. Recurrence risk and metastatic potential are high, with median survival of approximately 30 months across all ages (42, 71). Low response rates to chemotherapy and radiation therapy for MPNST have focused efforts on the development of novel medical therapy and carefully coordinated clinical trials to improve patient outcomes (75).

NF1 is associated with vasculopathy affecting multiple sites, including abdominal, renal, spinal, and intracranial vessels, with various consequences. The best-recognised manifestation of NF1 vasculopathy is hypertension secondary to renal artery stenosis. Blood pressure should be monitored at least annually, and hypertension should be investigated by renal artery ultrasound/Doppler, with surgical or dilation therapy to treat stenotic lesions. Most cases of hypertension in NF1 are essential hypertension and respond to medical management. Phaeochromocytoma is a very rare complication of NF1 but should be screened for in patients with elevated blood pressure. Cerebral vasculopathy affects 2% to 5% of children; 30% of these cases present with symptoms associated with ischaemia, but the others are diagnosed incidentally. Aspirin is recommended for patients with evidence of vasculopathy on neuroimaging (76).

Epilepsy occurs at an increased frequency in patients with NF1, affecting 3.8% to 7% of children(77), often in association with cerebral tumors and cortical malformations(78, 79). In a series of 14 cases, 29% were drug-resistant (80). A recent report documented infantile spasms in 0.76% of NF1 patients, compared with 0.02% to 0.05% in the general population (81).

Headache is common in NF1, and may go unrecognised. In a recent study of headaches in adults, as many as 65% of patients experienced migraines (ages 16-67 years, mean 36 years) (82). Although most headaches are not associated with

29 intracranial lesions, MRI should be performed in patients with severe or recurrent headaches or features suggestive of increased intracranial pressure. Orthopaedic complications of NF1 during childhood include scoliosis and long bone pseudoarthrosis, which may require operative management (83). Scoliosis occurs in about 20% of patients with NF1, but only about 5% require surgical intervention. More severe scoliosis tends to present earlier (at 5–10 years of age) and is often associated with vertebral dysplasia or bony lesions due to an adjacent plexiform neurofibroma. Bony defects of the tibia or other long bones are congenital and usually present with bowing or fracture on weight bearing. Fracture can sometimes be prevented by protective bracing and bisphosphonate therapy. Bisphosphonate therapy has also been shown to promote healing after surgery in mouse models(84). Individuals with NF1 are prone to osteopenia which may progress to osteoporosis over time(85), for which bisphosphonates may also have a role(86).

Treatment Treatment approaches for NF1 are diverse and depend on the specific clinical problem. General approaches to therapy are summarized as key points below.

Early intervention including physical therapy, occupational therapy, and speech therapy are recommended for children with NF1 and developmental delay. No controlled studies have evaluated the benefit of treatment.

• Surgery usually is not necessary in NF1. It may be considered for selected symptomatic cutaneous and subcutaneous neurofibromas and complicated plexiform neurofibromas, as well as for large OPGs causing mass effect and hydrocephalus with significant visual impairment (87).

• Complications of surgery for plexiform neurofibromas include excessive hemorrhage and neurologic deficit due to nerve damage (40, 45).

• Early diagnosis and surgical resection with wide margins has been the mainstay of treatment for MPNST (88). While chemotherapy to date has lacked efficacy (75), molecularly targeted approaches to medical therapy continue to be an important focus of ongoing research (21, 89).

30 • Safety and efficacy of surgical correction of scoliosis in NF1 has been demonstrated in a case series including 32 children between 11 and 19 years of age with follow-up for an average of 6.5 years (90).

• Surgery including encephaloduroarteriomyosynangiosis (known as EDAMS or pial synangiosis) may be indicated in the management of moyamoya in NF1 (91).

• Cranial radiotherapy is usually avoided in NF1 because of the increased risk of occlusive cerebral vasculopathy (moyamoya) and secondary tumor formation (92, 93).

• Radiotherapy occasionally may be used as a palliative treatment for inoperable MPNSTs or as an adjunct to surgical resection or novel medical approaches, when the risks of progression or recurrence are thought to outweigh the risks of secondary malignancy (21, 71).

• Data from the first randomized, double blind placebo-controlled trial of statin therapy for cognitive dysfunction examined the effectiveness of simvastatin in 62 children with NF1. No significant benefit was demonstrated overall, but a number of methodologic limitations were cited (94). The potential benefit of statins was further evaluated in an international multicenter trial using lovastatin, providing Class I evidence of no improvement in visual spatial learning or attention in this population (59), indicating this treatment should not be used.

• Vincristine and carboplatin chemotherapy is the current standard of care in children with symptomatic progressive OPG in NF1 (21). Outcomes of chemotherapy for children with NF1 treated with vincristine/carboplatin regimens have included stabilization of vision in 40% and improvement in 31%; vision deteriorated in 29% of children studied (63). The efficacy of new agents (including RAD001) is under investigation, with a view to biologically targeted treatment in future (21, 95).

• Precocious puberty may require treatment with gonadotrophin analogues.

• There are currently no proven medical therapies to treat plexiform neurofibromas as standard of care. Early clinical trials employed

31 differentiating agents, antifibrotic agents, immune suppressants, and angiogenesis and farnesyltransferase inhibitors without significant benefit (26, 96-98). Some disease activity has been demonstrated with attenuation of c-kit signaling using imatinib (68) (see Chapter 4), pegylated interferon (99), and inhibition of mitogen-activated protein kinase kinase (MEK inhibitor, selumetinib) (70). Hopefully additional data will be available in the near future to outline medical approaches for use in routine clinical care.

• Aspirin is recommended for patients with evidence of vasculopathy on neuroimaging (76).

• Pain associated with nerve tumors may be treated with agents such as gabapentin, but there are no specific data reporting optimal dose or efficacy in NF1 patients.

• Psychological interventions to support social-emotional functioning are indicated alongside pharmacologic pain management (67), and to support children with anxiety or mood disorder associated with chronic illness.

• Seizures are treated with antiepileptic drugs including carbamazepine and lamotrigine, with careful consideration of the potential for increased risk of side effects on bone health and cognition (40).

Multicenter clinical trials are under way to identify improved treatment options for the major complications of NF1 (21, 24). Results are awaited from a number of studies, including assessing the utility of the mTOR inhibitor rapamycin, the VEGFR (vascular endothelial growth factor receptor) and the protein tyrosine kinase inhibitor imatinib in treating children with plexiform neurofibromas. Multiagent regimens include the angiogenesis inhibitor bevacizumab with the mTOR inhibitor RAD001 for MPNST, and the epidermal growth factor receptor (EFGR) inhibitor erlotinib with mTOR inhibitor rapamycin for low-grade gliomas (100, 101). The observation of rapidly progressive moyamoya in a child with glioblastoma treated with the angiogenesis inhibitor bevacizumab indicates that the NF1 population may be at increased risk of adverse effects from this class of medication (102).

32 Conclusion A number of key management challenges exist for children with NF1. Effective surveillance to identify problems early offers the opportunity to optimize care. An individualized approach is needed, particularly for management of the variable manifestations of plexiform neurofibromas. Multimodal therapy will continue to be important for children with NF1, given the diverse range of complications arising in this condition. However, it is hoped that effective and tolerable medical treatment options will increasingly become available with improved outcomes in the near future.

33 CHAPTER 3. COMPLICATIONS OF SPINAL NEUROFIBROMAS IN CHILDREN WITH NEUROFIBROMATOSIS TYPE 1: ILLUSTRATIVE CASES AND LITERATURE REVIEW.

Introduction Neurofibromas and plexiform neurofibromas (PNF) are benign neural tumours comprising key diagnostic features of Neurofibromatosis type 1, the most common neurocutaneous tumour suppressor syndrome occurring in childhood, with an incidence of 1:3,000 (103). Plexiform neurofibromas can cause significant morbidity and have been associated with an increased mortality rate in children with NF1(104).

Neurofibromas occur as discrete bundles of neural and fibrous tissue in cutaneous, subcutaneous or deeper tissues, including around spinal nerve roots(26, 40). Whilst cutaneous and subcutaneous tumours typically arise during middle childhood onwards, plexiform neurofibromas are predominantly congenital lesions(65, 105). Plexiform neurofibromas are more complex peripheral nerve sheath tumours, which may be diffusely infiltrating with indistinct margins, extending along the length of a nerve and involving multiple nerve fascicles (65), located around superficial or deep nerves. They may be associated with externally visible increased tissue bulk, cutaneous hyperpigmentation or hypertrichosis (65, 106). Although all neurofibromas can cause cosmetic disfigurement, cutaneous and subcutaneous tumours otherwise cause only minor symptoms including pruritis and discomfort(106). Significant symptoms and signs of plexiform neurofibromas occur due to compression or displacement of nerves and other adjacent structures, and vary dependent on size and location of the tumour. These tumours are richly vascularized, and may stimulate underlying bone growth causing bony dysplasia(26). Although growth rates for individual tumours vary over time, most rapid growth occurs during early childhood(28, 107).

Whilst clinical studies typically identify about 25% of individuals with externally evident PNF(65, 106), internal PNF are demonstrated on MRI in between 40-60% of patients(66, 107, 108), leading to symptoms in about half of affected individuals(66).

34 Reports outlining incidence and complications of neurofibromas in the spinal region are limited in both adults and children with NF1. Incidence of spinal tumours in childhood has been reported at 13.5% in a series of 62 consecutive asymptomatic children with NF1 aged 11 months to 18 years (109). Over time, about 40% of individuals with NF1 have spinal tumours(110, 111), with about 2% experiencing significant symptoms (106, 111).

Neurofibromas and spinal deformity may cause significant pain, paresis with risk of complete paralysis, respiratory compromise or bladder/bowel dysfunction. Children with PNF in this location have been over-represented in early clinical trials between 1996-2007, reflecting the severity of associated neurologic and orthopaedic complications. Spinal cord compression was present in 24% of children, with potential cord compression affecting a further 23%, among 59 children treated (96).

It is essential that clinicians are aware of the potential complications attendant on tumours in the spinal region in NF1, to ensure appropriate surveillance and treatment is instituted to minimize morbidity and risk of early mortality. A series of illustrative cases are presented here outlining the potential complexities of neurofibromas in the spinal region, and highlighting important clinical clues to alert the clinician to investigate and treat promptly to optimize patient outcome. Key messages are summarized in Panel 3.1. Approaches to management of neurofibromas and associated scoliosis in children with NF1 are reviewed and discussed.

This project was approved by the local Human Research Ethics Committee (HREC reference LNR/17/SCHN76).

Clinical Cases The children described here attended the Neurogenetics Clinic at The Children's Hospital at Westmead between July 2009 and January 2016 (summarised in Table 3.1, followed by individual case descriptions).

35 Panel 3.1 Spinal/Paraspinal Neurofibromas: Characteristic Features and Principles of Management

PNF occur on any nerves in 50-60% of patients with NF1 PNF occur around the spinal region in approximately 13% of NF1 patients Spinal neurofibromas are symptomatic in about 2% of individuals with NF1 Neurofibromas along multiple spinal nerve roots may be associated with plexus and peripheral nerve involvement with risk of respiratory insufficiency, muscle wasting and weakness, bladder and bowel dysfunction

Risk factors for / symptoms of spinal tumours in NF1 include: • Externally visible PNF overlying the spine/neck/limb girdles • Large hyperpigmented macules or hypertrichosis overlying the limbs or spine • Back Pain • Abdominal Pain • Scoliosis • Hyperreflexia • Focal muscle wasting or weakness • Gait abnormality

Spinal instability and subluxation are more common in association with PNF. Spinal MRI is mandatory in the presence of neurologic symptoms/signs and should be considered in the presence of PNF/skin changes overlying the spine/limb girdles or scoliosis. Ongoing clinical and neuroimaging surveillance for spinal PN is indicated on a 6-12 monthly basis. Active surgical treatment should be considered in the presence of significant focal cord compression or progressive neurologic deficits. Medical treatment may be considered to treat sub-acute progressive lesions with close monitoring. Chronic pain requires multimodal treatment including pharmacologic and non- pharmacologic therapy. Rapidly increasing pain, progressive focal neurologic signs and tumour growth should prompt surgical review and investigation for malignant transformation to MPNST (lifetime risk of 8-13% in any individual). PNF-plexiform neurofibroma; MPNST-malignant peripheral nerve sheath tumour

36 Table 3.1 Characteristics of children with spinal/paraspinal plexiform neurofibromas

Patient Age/Sex External appearances PNF location Scoliosis Kyphosis Neurologic Spinal cord Indication for Operative Morbidity/functional (years; F/M) spine / Overlying (region)* examination Involvement Spinal MRI Intervention Impairments** cutaneous changes on MRI (age, years) 1 11 M Nil Spinal nerve root No No Hyperreflexia Compression / Abdominal pain Tumour resection Nil Displacement (10) T10 2 15 F Nil Paraspinal; T10-L1 No Assymetric brisk Compression/ Complex NF1 Tumour Gait disorder Large unilateral foot/leg patellar jerks Displacement History of resected resection (due to leg/foot PNF) abdominal tumour (11) Ant/post fusion for kypho-scoliosis (14) 3 14 F Extensive Shoulder/arm/cervical C4-C6 Yes Hyperreflexia Compression Hyperreflexia Tumour resection Mild left arm weakness hyperpigmentation over spine (post-op) Left arm weakness (10) the upper arm extending to hand; Halo traction + Normal spine fusion for progressing to subsequent asymmetry of shoulder subluxation girdles

4 8 F Extensive Midline lower back No No Hyperreflexia No Hyperpigmentation - Pain, anxiety hyperpigmentation over extending R>L buttock; Midline back posterior pelvic girdle Small superficial upper tissue bulk and upper back back Pain

5 8 M Deep purple bulky Unilateral face/neck C1-T1 Severe Hyperreflexia Traction/ Cervical tumour; Tumour debulking Pre-operative recurrent transient tumour resembling compression Hyperreflexia and fusion episodes of paraparesis; haemangioma (8) Post-op no fixed neurologic deficits; Pain; Home schooling for risk minimisation

6 18 F Nil Extensive tumour load: No No Hyperreflexia Bilateral spinal Spinal involvement Focal tumour Arrest of progressive deficits post- Multilevel spinal nerve evolving to cord noted incidentally resection op; roots; hyporeflexia, compression on imaging (c-spine;17) Residual wasting, weakness, pain, Brachial and lumbar plexi; wasting, C2-C5; head/neck PNF sensory deficits, bladder and bowel Multiple peripheral weakness, pain, dysfunction; respiratory nerves; sensory deficits, Expansion of insufficiency; Head/neck bladder and bowel multiple spinal Anxiety/depression dysfunction*** nerve roots

7 18 F Overlying cutaneous Posterior C/T/L Yes Hyperreflexia No but Fusion T3-T10 fusion Pain/dysaesthesia; Respiratory changes extensive insufficiency; chest/paraspinal Dysaesthesia R (3 years) (3) dural ectasia (paraspinal purplish arm Short stature; Inoperable discoloration consistent Cosmetic deformity; with PNF) (18) Anxiety/depression *C-cervical; T-thoracic; L-lumbar; **No deficits due to operative intervention; ***Multifactorial presumed due to cord compression, radiculopathy and peripheral nerve involvement; PNF-plexiform neurofibroma.

37 Case 1 This 11-year-old boy had a background of hypothalamic low grade presumed astrocytic tumour diagnosed at age 3 years, managed conservatively without visual or endocrine impairment. There were no externally visible PNs. At age eight, persistent left lower quadrant abdominal pain occurred. An abdominal ultrasound was normal. On review several months later, there was no localised pain on spinal palpation, full range of movement and no abnormalities of the peripheral neurologic examination. Some constipation was reported. Due to persistent abdominal pain, an MRI of the spine was arranged which demonstrated a lobulated mass at T10 expanding the left neural exit foramen and causing severe displacement and cord compression (Figure 3.1a,b). Surgical decompression and tumour resection arranged within 10 days confirmed PNF on pathology, and was followed by resolution of abdominal pain. Four years later, residual tumour increased in size within the canal, without significant cord compression, but with extension to involve the paraspinal area

b c

Figure 3.1 Case 1. MRI of eleven year old child with left abdominal/flank pain due to left transforaminal spinal neurofibroma at T10/T11 (coronal STIR, a); at maximal cord compression (axial T1 weighted gadolinium enhanced view; spinal cord =long white arrow; neurofibroma = short white arrow, b); sagittal T2 weighted image showing anterior displacement of the spinal cord (c).

38 outside the canal. No new symptoms occurred. He proceeded to repeat debulking of the spinal lesion. Pathology showed atypical findings concerning for malignant peripheral nerve sheath tumour, including increased cellularity, extent and severity of atypia, and presence of mitoses. A subsequent operation occurred to ensure complete tumour excision, which was uncomplicated. He remained well five months later.

Case 2 Now aged 15 years, this girl born to non-consanguinous Arabic parents was diagnosed with maternally inherited NF1 aged 3 years having café au lait macules (CALM) and axillary freckling, with leg length discrepancy and gait assymetry due to a large left foot PNF, and several xanthogranulomata over the trunk. She was reviewed in our service following arrival from overseas at age 11 years. Interval history was reported to include resection of a retroperitoneal abdominal mass identified as a PNF, and bowel resection for intussusception within the preceeding year. The left leg and foot PNF was associated with a 5cm leg length discrepancy for which she required a larger shoe size, and elevated sole for the unaffected side. Thoracolumbar scoliosis was noted in Neurogenetics clinic. Orthopaedic evaluation attributed this to pelvic asymmetry rather than true scoliosis. No palpable abdominal mass was found and the examination was remarkable for abnormal gait due to leg length discrepancy, and hyperreflexia at the knees, right greater than left. An MRI of the abdomen and spine was performed given hyperreflexia, and to characterise the reported retroperiotoneal and abdominal lesions as a baseline for monitoring over time. Spinal MRI revealed kyphoscoliosis at T11/T12 convex to the right, with moderately sized paravertebral PNF involving T10 to L1 nerve roots with intraspinal extension at T11, erosion of the right T11 posterior vertebral body with dural ectasia; significant displacement and compression of the spinal cord was identified (Figure 3.2 a-d). No previous films were available for comparison to indicate whether this was a static or progressive lesion. The patient was re-examined, with lack of signs of myelopathy other than hyperreflexia confirmed. T10-T12 laminectomy with tumour resection was performed, due to concern regarding potential acute vascular compromise in the event of tumour growth. Pathology confirmed PNF.

Figure 3.2 Case 2. T2 weighted coronal (a), sagittal (b) and axial (c/d) MRI aged 11 years showing neurofibroma at T11 with severe cord compression and displacement; lobulated PNF in adjacent peritoneal cavity T10-L1 (a); widening of the right neural foramen at T11 with scalloping of the posterior vertebral body and dural ectasia (c/d); spinal cord indicated by white arrow.

40 Two years later, the patient’s symptoms remained static without back pain. Gait asymmetry persisted with no interval change in examination. Three years later, progression of the kyphoscoliosis was identified with minimal change in the tumour. A two-stage anterior and posterior spinal fusion (T10-L2) was conducted with stabilization of the curve, without complications.

Case 3 This 14-year old girl was followed for several years in clinic. Examination revealed a slim child with an extensive area of hyperpigmentation extending from the left elbow down the arm to involve the ulnar distribution of the hand with increased tissue bulk notable above the elbow, consistent with extensive left arm PNF (Figure 3.3a-b). Deep tendon reflexes during serial examinations were brisk with ankle clonus (arms greater than legs, right greater than left; mild weakness of the left arm). At 10 years of age, spinal MRI demonstrated extensive PNF underlying the area of hyperpigmentation involving the left brachial plexus, peripheral nerves of the left arm, paravertebral involvement from C4 to T3 including cervical spinal nerve roots, extension into the spinal canal with displacement and compression of the cord from C4-C6, together with cord T2 and FLAIR hyperintensity, and associated cervical scoliosis (Figure 3.3c-e). C3-C6 laminectomy with tumour debulking was performed 9 days later. Postoperative pain was treated with gabapentin with improvement, then tapered off over 3 weeks. The patient was seen in clinic with pain only on palpation of the PNF, and stable mild weakness noted in the LUE (4/5). Repeat plain films (Figure 3.3f) and MRI of the spine 6 months later showed anterior subluxation of C3/C4 with acute cervical kyphosis and spinal canal stenosis without symptoms or signs of cord involvement. The patient was managed with 6 weeks of traction, followed by anterior and posterior fusion (C3-C6). Three years later she continues well without pain or progressive neurologic deficit.

a b c

d e f

Figure 3.3 Case 3 aged 10 years with large CALM over the left shoulder/arm and shoulder asymmetry (L>R; a-b); MRI spine coronal STIR image showing L paraspinal PNF with intraspinal and axillary extension (c); axial T2 weighted images showing cord compressed anteriorly and to the right (white arrows) with transforaminal tumour extension to multilobular PNF left neck (d); sagittal T2 weighted images showing midline neurofibroma at C3-5 causing anterior spinal cord displacement and left paraspinal PNF (e); anterior subluxation of C3/C4 6 months after tumour resection (lateral x-ray, f).

42 Case 4 An 8-year-old girl with extensive hyperpigmentation over the upper and lower back was noted to have subtle increased tissue bulk underlying the lower back skin changes during early childhood (Figure 3.4).

Figure 3.4 Case 4 (at age 5 years) with diffuse hyperpigmentation over the upper back and upper buttocks extending over the anterior hips bilaterally (a-c). Subtle increased soft tissue bulk over the midline lower back (c, d white arrows) due to plexiform neurofibroma.

Lower back pain radiating to the buttocks occurred from 4 years of age, such that prolonged sitting caused significant distress, and was treated with 35mg/kg/day gabapentin. Deep tendon reflexes were symmetrically brisk, particularly in the legs. MRI showed increased bulk of the medulla and cervical spinal cord (not shown), along with cutaneous and muscular plexiform neurofibromas over the lumbar region without extension to the spinal canal (Figure 3.5). Minor superficial PNF was seen in the upper thoracic soft tissues. Chronic pain particularly on compression of the PNF contributed to significant concern about falling in the playground, along with separation anxiety and need for increased supervision at school.

43 a

b Figure3.5 Case 4 a. Axial STIR MRI showing plexiform neurofibroma over the lumbosacral spine and buttocks without extension to the spinal canal. c b-c. Coronal STIR MRI showing buttock plexiform neurofibroma extending into deeper muscle layers on the left buttock.

Psychological support was provided for anxiety, along with ongoing analgaesics. Persistent increasing pain paralleled gradual expansion of tumour, without involvement of the spinal canal. Trametinib was commenced due to significant

44 functional impairment associated with pain. After 6 months of therapy, pain and anxiety are significantly improved, with daily analgaesic discontinued and normal participation in school and community activities, with radiologic monitoring underway to track tumour volumes.

Case 5 Patient 5 is a 12-year old boy, diagnosed with head and neck haemangioma at the time of birth. The expected regression of the haemangioma during the early years of life did not occur. At the age of 4 years he was reviewed by a paediatric neurologist who identified café au lait macules with skin fold freckling, and diagnosed NF1. Increased tissue bulk was noted in association with the deep purple discoloration of the skin affecting the left side of the mandible and neck, extending down over the left shoulder. MRI of the head and neck was arranged which showed imaging findings consistent with a highly vascular PNF (Figure 3.6).

Figure 3.6 Case 5 at age 4 years showing T2 weighted sagittal MRI of the cervical spine showing severe kyphosis with dysplasia affecting the vertebral bodies and posterior spinal elements. PNF anterior to C1-C5 with extension into the spinal canal, causing posterior displacement and compression of the cord.

45 Significant kyphoscoliosis was evident on MRI, more obvious than on clinical examination due to bulky tumour overlying the spine, with deep extension anterior to the vertebral bodies and within the spinal canal causing cord compression and displacement. The patient proceeded to have an episode of acute quadriplegia lasting minutes following a fall from a bed onto a carpeted floor. The presumed mechanism was due to tension across the spinal cord during neck flexion/extension. Surgical treatment was considered by a multidisciplinary team of neurosurgical and orthopaedic specialists experienced in the management of patients with NF1. The family was not keen to proceed due to the risk of significant surgical complications. Investigational medical therapy was also considered, and deferred due to concern regarding destabilisation of the spine in the event of tumour shrinkage. The child was managed conservatively, with restrictions placed around activity to minimize excessive neck movement. His parents elected home schooling due to concerns about the risk of minor trauma in the school environment. Several subsequent episodes of transient paraplegia occurred prompting multidisciplinary reviews at intervals, leading to surgical intervention consisting of soft tissue debulking, decompression of the foramen magnum and posterior c-spine decompression with fusion from occiput to T5. Six months later persistent neck pain has been managed with gabapentin, and the patient has no significant neurologic deficits.

Case 6 This young woman, with maternally inherited NF1 experienced multiple severe complications, including an extensive PNF of the head and neck. This lesion involved the periorbital region, external auricular canal, and intraoral area with thickening of the tongue associated with dysarthria and swallowing difficulties. Multiple cutaneous neurofibromas became evident during middle childhood. Deep tendon reflexes were symmetrically increased during middle childhood. Neurofibromas affecting spinal nerve roots at multiple levels were demonstrated on MRI of the head and neck, with extended imaging over time showing high tumour burden involving neurofibromas on all spinal nerve roots, brachial and pelvic nerve plexi, and major peripheral nerves in all four limbs (Figure 3.7a-b). Several well circumscribed tumours were identified within the spinal canal between C1-C4 and C6-C7.

Figure 3.7 Case 6 Extensive PNF tumour load shown on whole body MRI coronal and sagittal STIR images at age 17 years (a,b) including enlargement of spinal nerve roots (white arrow, b) at all levels; T2 weighted sagittal cervical spine aged 8 years (c) and 18 years (d) showing progressive growth of neurofibroma anterior to C1/2 vertebral bodies and multiple tumours in the upper cervical region; cord compression from bilateral spinal nerve root tumours (axial STIR e-f); right facial PNF with tongue involvement (c,f).

47 Progressive functional impairments occurred during late adolescence, including muscle wasting, weakness, leg pain (treated with gabapentin 50mg/kg/d) and multifactorial gait impairment with bilateral foot drop and unrecordable lower extremity NCS, reflecting peripheral neuropathy. Surgical treatment included repeated debulking of head/neck PN. However, surgery for spinal/pelvic disease was not recommended due to the diffuse extensive PNF involvement. At age 17 years (2012) a course of imatinib (Glivec) was prescribed at 300mg bd, increased to 400mg bd. Despite therapy, tumour volumes slowly increased, and progressive decline in clinical status occurred including requirement for nocturnal CPAP, loss of bladder and bowel function and progressive weakness. Imatinib was ceased after 12 months. The patient required a tripod walking aid for support and balance. At age 17 years, rapid decline in gait occurred over a few weeks, requiring a wheelchair. Repeat spinal MRI showed growth of upper cervical masses at multiple levels (Figure 3.7 c-d), with progressive cord compression (Figure 3.7 e-f) and T2 signal hypersensitivity indicating cord oedema (not shown). C1-C4 laminectomy and C6-C7 laminoforaminotomy with tumour debulking were performed, pathology confirming neurofibromas. Clinical status stabilized with return of aided independent mobilization over short distances and power of 4/5. A high suspicion for risk of transformation to malignant peripheral nerve sheath tumour continues to be maintained during subsequent clinical follow up given the patient’s massive tumour burden.

Case 7 An 18-year-old girl diagnosed in early childhood had PNF over the left posterior chest wall with early onset progressive thoracic kyphoscoliosis (Figure 3.8a). Anterior and posterior spinal fusion (T3-T10) with bone allograft was performed at 3 years of age. Over subsequent years, progressive curvature occurred above and then below the fused spinal region. By age 11 years, upper thoracic and cervical scoliosis was evident on examination with imaging demonstrating progressive severe dural ectasia and gradual growth of the thoracic PNF. Dysaesthesia (tingling and numbness) affecting the right arm and shoulder blade became more prominent at 14 years, extending to involve the axilla with radiation down the right arm, and increasing pain from 16 years. MRI showed progressive spinal curvature with profound dural ectasia,

a b Figure 3.8 Case 7 Coronal STIR MRI at age 3 years showing left thoracic kyphoscoliosis with adjacent PNF (white arrow, a); Coronal (b) and axial (c) T2-weighted MRI showing progression of scoliosis with significant expansion of the spinal canal and dural ectasia at age 18 years; adjacent PNF then showing prominent nodular component c (white arrows).

osteopenia and minimal change in the soft tissue mass. Investigations were performed to assess for MPNST including biopsy of the left chest nodule (Figure 3.8 b, c, white arrows), pathology consistent with PNF. Nerve conduction studies showed no major sensorimotor changes. Respiratory insufficiency developed, along with anxiety and mood disorder in the context of significant cosmetic deformity with short stature, and chronic illness requiring ongoing active management. Pharmacologic treatment with gabapentin and SSRIs was instituted along with non-pharmacologic measures. Symptoms were attributed to radiculopathy associated with dural ectasia (Figure 3.8 b, c), with ongoing careful surveillance for MPNST. Consultation between experienced neurosurgeons and orthopaedic specialists occurred with international colleagues, recommending conservative management given significant operative risks.

49 Discussion The cases presented illustrate a diversity of symptoms and signs attributable to the neurologic and orthopaedic complications of spinal/parapsinal tumours in NF1. Comprehensive clinical assessment including general and neurologic examination during routine clinical reviews is mandatory, to identify and treat such complications. Paediatricians are trained to recognize a range of red flags suggestive of spinal pathology that can occur in children with NF1, including back and abdominal pain, weakness, bladder or bowel dysfunction and abnormalities in the neurologic examination. Additional NF1-specific clues associated with externally visible plexiform neurofibromas over the spine or limb girdles include increased tissue bulk, pigmentary changes or hypertrichosis, and scoliosis. The presence of both subcutaneous and plexiform neurofibromas in the same patient should raise suspicion, potentially indicating a higher tumour burden, as this was strongly associated with a higher incidence of internal PNF in one retrospective study (OR 6.8)(112), although this has not been noted in other studies(105).

The importance of comprehensive and timely evaluation of severe or persistent back and abdominal pain in childhood to identify and treat spinal tumours and cord compression has been emphasised previously(113-116), and certainly applies in the management of children with tumour predisposition syndromes such as NF1 as illustrated by Case 1. The origin or extent of abdominal masses must also be established, bearing in mind possible spinal involvement, which has been reported in a child with NF1, associated with development of MPNST(117).

Cutaneous changes or increased tissue bulk associated with PNF overlying the spine or limb girdles should raise the clinician’s suspicion of tumour extension into the spinal canal or underlying bony involvement, as described in in Cases 3, 5 and 7. In contrast, neuroimaging may exclude deep spinal involvement as in Case 4 despite superficial hyperpigmentation with PNF. This child experienced significant functionally impairing pain, requiring both pharmacologic and non-pharmacologic treatment. Similarly, brisk reflexes may occur with or without the presence of significant cord pathology. Careful clinical surveillance remains essential to monitor for changes that may indicate repeat neuroimaging is necessary over time.

50 Scoliosis is recognized as a red flag in all children with back pain(113), and commonly occurs in association with spinal tumours in NF1(118). In a series of 53 children with NF1 (mean age 9.6 years, range 11 months-18 years) and normal neurologic examination, routine screening spinal MRI was performed to assess the yield for tumour diagnosis. Seven (13%) children with spinal neurofibromas (aged 5 to 18 years; four solitary neurofibromas, and three PNFs) were identified (109). Scoliosis was coincident with spinal tumours in 5 of these 7 patients (109), constituting an important clinical clue to underlying tumour. Two patients were treated with surgical resection due to intradural tumour with significant cord compression in one and due to the development of associated thigh pain in the other. Clinical management/outcome was altered in only 1.9% (1/53) indicating routine spinal imaging was not justified for all children with NF1, and should be directed by clinical suspicion of spinal pathology, including presence of scoliosis (109). Other neuroimaging studies for individuals of all ages with NF1 and recognized scoliosis have demonstrated presence of associated tumour in 37% of cases(118).

Orthopaedic management by specialists experienced in NF1 is essential to correctly characterise scoliosis as dystrophic, having a range of associated dysplastic features(118, 119), or non-dystrophic, due to differences in the natural history and recommended management approaches. Whilst non-dystrophic scoliosis in NF1 behaves like idiopathic scoliosis, the dystrophic variant can occur in very young children, is more likely to result in relentless progressive spinal curvature and to occur in association with adjacent spinal tumours. Bracing is ineffective in dystrophic scoliosis(118, 119). Spinal MRI is important in monitoring scoliosis in NF1 to identify evolution of non-dystrophic to dystrophic curves over time (which was reported in 80% of cases in one study of all ages)(119, 120), and to assess for intraspinal and paraspinal tumours(121). Tumours adjacent to the spinal convexity are common in dystrophic scoliosis(121). Clinicians must also be monitoring for the presence of kyphosis which is more strongly correlated with risk of neurologic deficit from the spinal deformity(118).

Early aggressive surgical management for dystrophic scoliosis is recommended to stabilize the spine using anterior and posterior fixation with abundant autologous bone graft to minimize risk of non-union(118). Halo-traction prior to fixation should also

51 be considered for cervical kyphosis(120). The orthopaedic team should recognize the increased risks of spinal deformities associated with adjacent tumour in NF1 which have been well described over time (119), including destabilization of the spine, myelopathy, radiculopathy, cord compression, intraoperative bleeding due to hypervascularity of the tumour, and the need for multi-stage procedures to resect tumour and adequately stabilize the spine (118, 120). Spinal deformity and instability is at least twice as common following laminectomy for removal of spinal tumours in children compared with adults(122), and is expected to be higher in the NF1 population.

Spinal deformity with adjacent neurofibroma may cause significant nerve or cord compression (120) (as in Cases 1-3, 5-6), or excessive traction on the spinal cord or exiting nerve roots (as in Cases 5 and 7). In one case series, sixteen percent of 102 patients with NF1 and spinal deformity were found to have spinal cord or cauda equina compression(119). For those individuals having high cervical/paraspinal tumours with kyphoscoliosis, assessment of respiratory function is essential.

Dedicated diagnostic spinal imaging in children with NF1 should be arranged to evaluate concerning symptoms and signs, to monitor for change in known tumours, and for surgical planning purposes. While routine spinal imaging has been advocated for NF1 in the past(123), most authors recommend imaging based on clinical suspicion only, because asymptomatic tumours may not require intervention (109, 111). Neuroimaging protocols for neurofibromas typically include STIR (short time inversion recovery) (124). Although WBMRI is increasingly used in management of NF1 in some centres, and may help to identify spinal tumours as part of an assessment of whole body tumour burden(66, 125), smaller tumours may be missed(126). The benefits of routine WBMRI have not yet been established outside a research setting in large clinical populations.

In cases where spinal tumour is identified with spinal cord compression or significant bony changes in children with NF1, establishing clinical and radiological change over time is essential. It is noteworthy that marked displacement of the spinal cord as seen in Cases 2 and 3, presented with limited symptoms and signs aside from hyperreflexia. This reflects the relatively slow growth rate of benign NF-1 associated

52 tumours. With initial identification of any tumour in the spinal canal, in the absence of neurologic symptoms and signs, conservative management may be appropriate, as the tumour may be in a static phase of growth. However, the potential for progressive growth and acute vascular compromise of the cord remains, along with risk of neurologic deficit secondary to bony dysplasia, which may prompt surgical intervention, as in our patients (Case 2 and 3) and others.

Characterisation of spinal tumours during a natural history study in a cohort of 97 symptomatic NF1 patients for whom spinal imaging was performed (median age 14.2 years, SD 7.6) showed the frequency of spinal tumours increases with age, 70% less than 10 years, 80% 10-18 years and 89% older than 18 years (127). The yield of spinal MRI for symptomatic patients has been reported as high as 96% in one NF clinic including all ages(111). In this study tumours were extradural in 33% of patients (18/54), 57% (31/54) had transforaminal tumours, while intramedullary tumours occurred infrequently (6%, 3/54 patients)(111) as in other case series(128). A predilection for the lumbosacral spine has been observed(129), though all spinal regions can be affected(111), as shown in our selected patients (Table 1). The entity of spinal neurofibromatosis is recognized in a subset of individuals with bilateral neurofibromas at every spinal level, and is characteristically associated with fewer other manifestations of typical NF1(130).

Children with neurofibromas in the spinal canal are likely to be among those who should be considered for active surgical and/or medical management. Surgical treatment is the primary mode of therapy for NFs in the spinal region. This may include acute tumour resection. Subacute intervention may be appropriate depending on the patient’s presentation with a view to resolution of existing symptoms and prevention of clinical deterioration. Whilst extensive multi-level disease associated with spinal NF1 is not readily amenable to surgical intervention, selective resection of neurofibromas causing focal cord compression may yield significant clinical improvement(131), as seen in our patient (Case 6). Unfortunately, not all patients experience improvement in symptoms such as pain or paresis following resection of plexiform neurofibromas. Furthermore, new neurologic deficits occur as permanent sequelae in a proportion of cases(104).

53 For some children and adolescents with NF1, the clinical consequences of NF1- associated tumours may reflect the impact of multiple lesions, which complicates surgical decision-making. This occurred for our patient Case 6 for whom progressive clinical decline occurred over late adolescence presumed due to multilevel transforminal spinal neurofibromas, PNF in the pelvis, lumbosacral plexus, and multiple peripheral nerves. Despite extensive disease, focused surgery was needed to halt the accelerated decline attributable to growth of cervical spine neurofibromas, and was provided with good effect in this patient.

In a retrospective assessment of children and young adults enrolled in early phase I treatment trials at the NIH from 1996 to 2007, spinal cord involvement was present in 24 percent, and identified as a potential complication in 47 percent (n=59, median age 8 years, range 2-21 years). The cervical cord was most frequently involved (7/24) with remaining patients having multi-level involvement (17/24)(96). Limited efficacy has been demonstrated with a range of agents with different mechanisms of action to date, including inhibition of RAS signaling(98), mTOR(69) and cKIT (68, 132), with MEK inhibitors showing the most promise recently with clinical trials ongoing. In certain circumstances, medical treatment should be considered for progressive lesions at risk of significant complications, with close follow up. Clinical and neuroimaging surveillance initiated based on clinical suspicion should commence from diagnosis to identify children with plexiform neurofibromas likely to cause significant symptoms during early childhood, to ensure optimal therapy, including selective use of novel medications where possible, ideally in the setting of a clinical trial.

There is currently inadequate evidence to recommend routine treatment of children with NF1 associated spinal tumours with targeted medical therapy. However, when possible, those with significant focal or multilevel spinal neurofibromas should be considered for medical therapy either in clinical trials or on a compassionate basis, so long as clinical and neuroimaging surveillance is frequent enough to allow identification of progressive disease that should be treated by surgical means.

The occurrence of chronic pain in the cases presented here represents another important management issue in this population. The impact of chronic pain associated with PNF in children and young people with NF1 was recently described

54 for a group of 59 individuals aged between 6-18 years(67). Despite analgaesic use in 33% of patients, impairment in daily living/quality of life was endorsed by 73% of parents, and 59% of youth (aged 10-18 years, N=41). Higher tumour burden was associated with increased pain, as were anxiety, depression and difficulties in social- emotional functioning(67), as also seen in our selected patients. Multidimensional treatment approaches are required including biological agents and psychosocial therapies.

During assessment of NF1 associated pain, clinicians must be cognisant of the risk of malignant peripheral nerve sheath tumour (MPNST) which is 8-13% during any individual’s lifetime (41). Increasing pain is one of the sentinel signs of sarcomatous change, representing a diagnostic challenge in NF1 due an overlap of this symptom in both benign and malignant tumours. As illustrated in Case 7, in the presence of significant spinal disease in NF1, pain may also occur due to mechanisms such as radiculopathy associated with dural ectasia. Nevertheless, increasing frequency and severity of pain, focal neurologic signs and rapid tumour growth should prompt investigation for MPNST(88). This entity portends the main threat of early mortality in NF1(43), with high likelihood of metastasis, frequent recurrence following resection, and poor response to chemotherapy and radiotherapy(89). Patients with high tumour load and NF1 whole gene microdeletion are at highest risk of MPNST. In NF1, sarcomatous change most commonly occurs in pre-existing neurofibromas or spinal nerve root tumour (88, 129). Although MPNST arising in the spinal region is rare for both sporadic and NF1 associated tumours (133), this can occur. A child diagnosed with NF1 initially presenting with bladder and bowel dysfunction was subsequently identified with spinal PNF and progression to MPNST (117).

Neuroimaging features suggestive of sarcomatous change include inhomogeneity of MRI signal intensity and patchy contrast enhancement in the tumor area (suggestive of necrosis and hemorrhage), with invasion of adjacent tissues(72, 129). High SUVmax on fluro-deoxy-glucose (FDG)-PET should raise suspicion and prompt consideration of tissue biopsy or tumour resection (134). MPNST have traditionally responded poorly to radiotherapy or chemotherapy(75, 89), with associated high risk of mortality(88). Identification of novel medications for treatment of MPNST with improved efficacy remains an active area of research(89, 135).

55 The genotype underlying NF1 was not available for most of the patients presented here based on limited routine clinical testing to date, due to the 5% false negative rate which mandates management for presumed NF1 anyway. Questions remain regarding the remarkable phenotypic diversity in different symptoms and signs affecting patients with NF1. Although many mutations have been described in the large NF1 gene, there are limited genotypes associated with a recognisable phenotype. One exception includes the NF1 microdeletion for which a high PNF tumour load and elevated lifetime risk of transformation to malignant peripheral nerve sheath tumour have been described(108). There may be a role for considering NF1 microdeletion testing in suspected cases. Other than the NF1 microdeletion, the entity of familial spinal neurofibromatosis has been acknowledged, for which missense or missense and splice-site germline NF1 gene mutations are more common(110). In the presence of resource limitation preventing genetic testing in all cases, maintaining a high index of clinical suspicion is mandatory. It is possible that over time, additional tumour suppressor or susceptibility loci will be identified, which may assist in understanding the phenotypic variability observed, and with risk stratification and directing follow up imaging intervals.

Conclusion In conclusion, outcomes for children with tumours in the intra/paraspinal region are variable in NF1, but morbidity is frequently significant, despite surgical and medical therapy [19]. A high threshold of suspicion for complications of neurofibromas including extension into the spinal canal is essential in management of children with NF1. This case series illustrates the following features as risk factors for spinal neurofibromas: cutaneous changes of externally visible PNF overlying the spine, limb girdles or adjacent limbs, scoliosis, presence of progressive back or abdominal pain, focal neurologic findings such as hyperreflexia, muscle wasting or weakness, bladder or bowel dysfunction. Recognition of the association between neurofibromas and spinal deformity, particularly dystrophic scoliosis and kyphosis of the cervical spine, is important to facilitate identification of potential complications early, to optimize surveillance over time, and to institute active management in a timely fashion with assistance of experienced orthopaedic colleagues, before permanent sequelae occur. With prompt surgical intervention and the promise of molecularly targeted medical

56 therapy, it is hoped that the severity and extent of complications associated with spinal tumours in NF1 can be avoided in future.

57 CHAPTER 4. NOVEL MEDICATION FOR COMPLEX NEUROFIBROMAS IN NF1

Introduction Plexiform neurofibromas (PNFs) are primarily benign tumours occurring frequently in patients with neurofibromatosis type 1 (NF1); they are usually congenital in origin. PNFs can cause significant disfigurement, and variable functional impairment depending on location and extent, including cranial nerve dysfunction, spinal cord compression, pain, and abnormal functioning of adjacent organ systems that may be encased by tumour (104, 105). According to population−based studies, approximately 25% of patients with NF1 have visible plexiform neurofibromas (PNFs) on physical examination (106), and additional lesions in deeper tissues are evident on imaging studies in between 50-60% of individuals (3, 9, 65, 66, 106). Studies of the natural history of PNF growth in NF1 have demonstrated that highest rates of growth occur in early childhood, and individual tumours vary in their growth trajectories over time (28, 107, 136).

Historically, surgical approaches have been the mainstay of treatment. However, surgery remains challenging due to the numerous lesions and extensive growth of many tumours, which can be diffusely infiltrating involving surrounding tissues. Risk of haemorhage requires careful management, and regrowth after resection is common (29, 65, 137). Systemic therapy offers the potential to treat multiple lesions concurrently without surgical risks. Candidate medications must have a tolerable side effect profile (138), along with demonstrated efficacy. Potential agents have been identified based on an understanding of tumour biology including the molecular pathways downstream of neurofibromin. Candidates have been summarised in recent years (21, 24, 26, 27, 30, 68, 70, 139), but none have so far been recommended for routine use.

Methodologic approaches for the study of novel medications for PNFs have been refined over time. Importantly, volumetric tumour analysis has been shown to be more sensitive for measuring change compared with traditional 2-dimensional measurement(28, 140). Occasionally tumour shrinkage has been observed without intervention, which may rarely occur as a biological phenomenon, but alternately

58 represents measurement error(29, 107). Previous studies have also indicated non- progressive lesions are less likely to respond to pharmacologic therapies (eg. siromlimus) (31, 69), suggesting the need to establish therapy during the most active phase of growth in childhood.

At our centre, three agents have been used on a compassionate basis for patients with complicated plexiform neurofibromas since 2009. Firstly, the mammalian target of rapamycin (mTOR) inhibitor sirolimus (Rapamune, Pfizer), secondly, the c-kit protein kinase inhibitor imatinib mesylate (Gleevec, Novartis) and thirdly, the MEK inhibitor trametinib (Mekinist, Novartis; inhibits the mitogen-activated protein kinase enzymes MEK1 and/or MEK2).

The most compelling evidence of potential efficacy for treatment of plexiform neurofibromas in mice and humans was for imatinib, at the time of this study. Rationale for use was based on recognition that c−kit−ligand is an important mediator of neurofibroma formation. Increased kit−ligand mRNA transcripts had been found in neurofibromas, and elevated serum kit−ligand detected in patients with NF1. In a mouse model of NF1, Yang et al. showed that loss of one copy of the NF1 gene in c−kit positive bone marrow−derived cells was sufficient to allow neurofibroma progression in the context of schwann cell NF1 deficiency, likely through activation of the c−kit receptor (141). They performed in vitro and in vivo experiments demonstrating reduction in tumour size and metabolic activity of neurofibromas in mice following pharmacologic attenuation of c−kit signaling using imatinib(132, 141, 142). Furthermore, remarkable clinical effectiveness was demonstrated in a single three-year-old child with life−threatening airway compression from an enlarging plexiform neurofibroma. Treatment with imatinib resulted in symptomatic improvement, and 70% decrease in tumour volume(141, 142).

Interim results of a Phase 2 trial of imatinib in a group of NF1 patients at that time suggested symptomatic improvement and reduction in tumour size in a proportion of cases, with final results published subsequently (68). In addition, imatinib had also been reported to show a favourable response in patients with NF1 and other tumour types such as metastatic gastrointestinal stromal tumours(143).

59 This chapter presents detailed results of treatment with imatinib in two patients with severe disease, illustrates principles of patient selection, along with the complexities of establishing optimal neuroimaging surveillance and monitoring of outcomes for PNFs in patients with NF1. A brief overview of other children selected for medical therapy using this and other agents, is also included.

Methods Patient selection-Inclusion/Exclusion Criteria A prospective audit of imatinib treatment for complex growing plexiform neurofibromas causing significant morbidity was conducted in patients meeting NIH diagnostic criteria for NF1, attending the Neurogenetics Clinic at The Children’s Hospital at Westmead (CHW). These were among the first patients treated for this indication in Australia.

The growth and morbidity associated with plexiform neurofibromas is monitored in this clinical service as part of routine care. PNFs that may be considered potential targets for medical therapy include the following: (i) head/neck lesions causing symptoms or the potential to cause symptoms with progressive growth (including airway compression, involvement of other vital structures, periorbital lesions with risk of obscuring the visual axis, and lesions with the potential to cause significant cosmetic disfigurement, typically involving the face) or (ii) peripheral nerve/spinal lesions (progressive neurological symptoms/signs, spinal cord compression, bone involvement with erosion or joint deformity, impingement on internal organs; ie. potential for progressive functional change). MRI tumour surveillance is established for patients with such lesions to record the pattern of growth, particularly for interpretation of changes on medication.

As part of the baseline pre-treatment selection process, patients were required to have evidence of progressive and symptomatic plexiform neurofibromas with ≥20% annual increase in tumour volume, and to be deemed unsuitable for alternative surgical treatment. Serial MRIs were acquired over time according to a neuroimaging protocol established for this study (Appendix 1); STIR (short T1 inversion recovery) images without gaps, including coverage of the entire lesion or region of interest. The

60 NFtumormetrics Group, Medical Imaging Centre, Massachussetts General Hospital, Boston, performed volumetric analysis. Information regarding surveillance versus treatment status was not provided to reporting radiologists.

Prior to treatment with imatinib, baseline haematologic, renal and hepatic function was performed. Malignant peripheral nerve sheath tumour (MPNST) was considered as a possible differential diagnosis, which would mandate investigation including PET scan, plus/minus tissue biopsy and alternative treatment, prior to inclusion (3, 74, 134). Additional details regarding inclusion and exclusion criteria are shown in Appendix 2.

Primary Outcome: Tumour Volume The primary outcome for efficacy was radiologic tumour response according to (i) true response ≥50% reduction in tumour volume, or (ii) partial response ≥20% reduction in tumour volume. Stable disease <20% change in volume could be considered to represent limited efficacy on a background of progressive disease. Progressive disease ≥20% increase in tumour volume was considered definite lack of activity.

Secondary Patient-Reported Outcomes: Symptoms and Quality of Life Secondary outcomes included clinical response assessed using a novel NF1 symptoms questionnaire, a simple linear overall wellbeing scale, quality of life (QOL) according to Medical Outcomes Study 36-Item Short Form (SF36) questionnaire, and adverse events/medication toxicity. Overall clinical response was assessed as: (i) improvement / resolution of symptoms, (ii) stable symptoms, (iii) disease progression/worsening of symptoms.

Improvement of symptoms and radiologically stable disease or reduced tumour volume, without significant medication related adverse events, was considered an overall effective treatment response.

An NF1 symptoms questionnaire was used to monitor disease activity consisting of 19 items focusing on symptoms and functional parameters routinely evaluated during a

61 comprehensive systems review (targeted to neurologic and oncologic symptoms) for complex NF1 patients. Items included headache, nausea, dizziness, pain, and gait impairment (Appendix 3). One additional open question was included. Frequency of clinical symptoms was scored on a 6-point scale where 0=nil, 1=less than monthly, 2=monthly, 3=weekly, 4=daily, 5=many times a day. A total score was calculated for each patient, with a higher score representing greater burden of symptoms, and potentially increased functional impact. Functional status was more extensively assessed using the SF36 questionnaire.

An estimate of overall wellbeing was derived using a linear scale ranked from low to high (Linear Overall Wellbeing Scale-LOWS, Appendix 3), where the overall wellbeing score was calculated as a proportion of the total length of the line (distance along the line/14.5).

The multidimensional SF36 questionnaire (Appendix 4) (144, 145), has become one of the most widely used general health status questionnaires(146). The SF36 requires patients to choose one of several responses to 36 questions across eight health domains: physical functioning, social functioning, role of limitations due to physical and emotional problems, vitality, general and mental health, and bodily pain (145). Questionnaires were scored using the method of Ware et al(145). Norms for the healthy Australian population were available from the Australian Bureau of Statistics for comparison with baseline patient responses in this study (147). In addition, the SF36 has been used in an adult population of individuals with NF1 (N=128, including 2 individuals <18 years), which showed a good correlation between clinical severity of NF1 as measured by the Riccardi scale, and SF36 responses(148).

Medication Administration and Monitoring Imatinib was administered orally, at a dose of 300-400mg bd for a 12-month period, under the supervision of CHW oncologists. Discounted drug was provided with support of pharmaceutical partner Novartis on compassionate grounds. Dose modification was considered if necessary in the event of medication toxicity, with particular reference to recognized adverse effects (Appendix 5).

62 Participants were initially reviewed monthly regarding symptoms, and blood monitoring (haematology, chemistry and liver function). Clinical evaluation, neuroimaging and administration of questionnaires were subsequently planned for intervals of 3, 6, 9 and 12 months after commencement of treatment.

Adverse Events Adverse events/medication toxicity was categorized according to the Cancer Therapy Evaluation Program Common Toxicity Criteria Version 4.0.

Additional children treated for PNF (outside the current protocol) Finally, characteristics of these two patients are considered briefly in the context of all patients treated with medical therapy at our centre to date, to highlight changes in approach evolving in recent years.

Approval for this study was obtained from the regional human research ethics committee (Protocol 09CHW154).

Results Two patients were selected for imatinib treatment, both aged 17 years as shown in Table 4.1. Patient 1 had bilateral thoracolumbar spinal disease causing pain and mild weakness with a spinal neurofibromatosis phenotype (Figure 4.1a-b)(130, 149). Regular analgaesics were prescribed including gabapentin and opioids. This adolescent was previously treated with sirolimus for approximately 36 months. Tumour shrinkage was not observed. A change in therapy was planned due to increasing pain and radiologic progression.

Patient 2 had a large right facial plexiform neurofibroma causing significant cosmetic deformity, involving the auricle, periorbital region, and lower face with deep extension to involve the tongue (Figure 4.1c; see also Chapter 3, Case 6). Extensive plexiform neurofibromas were seen throughout the body including bilateral spinal

63 Table 4.1 NF1 patients with complex progressive plexiform neurofibromas treated with imatinib at the Children’s Hospital at Westmead

Patient Age Genotype Indications PNF Location Volume Procedures Agent Duration Outcome Side effects (y) (mL) (N) (months)

1 13 c7258G>C Back/leg pain Multilevel spinal 1588.1 Nil Sirolimus 40m Progressive Nil heterozygous Muscle wasting neurofibromas disease splice site Leg>arm weakness Pelvic nerves mutation (independently mobile) c7258G>C

16 Urogenital dysfunction Imatinib 9m Progressive Nil including pain disease 2 17 NA Back/leg/other pain Large head/neck 9451.7 Facial PNF Imatinib 12m Progressive Hair loss; Muscle wasting peri-orbital; debulking (2) disease oedema Weakness Extensive spinal, (independently mobile) Pelvic nerves, Tongue PNF Neuropathy Peripheral nerves debulking (1) Bladder/Bowel dysfunction Perineal PNF (urinary catheterization; debulking (1) incontinence) Respiratory insufficiency (nocturnal ventilation) Cosmetic deformity

NA-not available

Figure 4.1 Coronal STIR MRI a. whole body, b. thoracolumbar spine (Patient 1); c. axial STIR face/neck, d. coronal STIR whole body (Patient 2).

disease, involvement of pelvic nerves, and multiple peripheral nerves (Figure 4.1d). Cervical cord compression was present. Several debulking procedures had been performed for the facial lesion with good effect, followed by subsequent regrowth. Debulking of a symptomatic perineal plexiform neurofibroma had been completed prior to treatment. The patient experienced leg weakness, sensory change with foot drop, pain treated with daily analgaesics, and bladder and bowel dysfunction. Nocturnal ventilatory support (BiPAP) had recently been commenced.

65 Imatinib treatment was commenced in 2012 at a dose of 400mg bd for Patient 1 for 8 months, and 300mg bd for Patient 2 for 6 months, increasing to 400mg bd for a further 7 months. Outcome measures were available at 8 months (both neuroimaging and patient reported outcomes, Patient 1), 10 months (patient reported outcomes, Patient 2) and 12 months (neuroimaging, Patient 2). Reason for cessation in both cases included inadequate response.

Primary Outcome: Tumour Volume Volumetric data for Patient 1 was available from 18 months prior to imatinib, to 8 months during treatment (Figure 4.2a). Tumour bulk increased by seventy eight percent in the eighteen months prior to imatinib treatment. At commencement of imatinib, spinal tumour volumes measured 1588.1mL. Four months after treatment, 13% volume increase was recorded, followed by -2.3% (versus baseline) by eight months. Overall, definite pre-treatment growth was observed, followed by stable disease.

For patient 2, the right facial lesion measured 762mL 18 months prior to treatment, with an estimated annual growth rate of 40.2% (Figure 4.2b). Unfortunately, follow up imaging to complement pre-treatment measurement was not available to monitor change in the facial lesion independently. Instead, whole body measurements were initiated from the start of treatment, including measurement of the facial lesion. Baseline tumour burden measured 9451.7mL, with 1.1% volume increase evident at 4 months, sustained at 12 months (Figure 4.2c), consistent with stable disease. Although not directly comparable, this stable volume contrasted with the background progressive disease evident on monitoring of the right facial lesion (representing 12% of whole body volume).

Secondary Patient-Reported Outcomes: Symptoms and Quality of Life NF1 symptom questionnaire scores and LOWS scores at baseline and over time are shown in Figure 4.3 and Figure 4.4 respectively, suggesting disease progression in Patient 1 and stable disease in Patient 2. One patient utilized the open question reporting pain during urination, defecation and sexual intercourse. Overall, responses did not demonstrate clear improvement with treatment. Although Patient 2 ranked

66 a. Patient 1 whole body pre- and post-treatment

2000

1500

1000

Volume (mL) 500

0 -18 -12 -6 0 6 12

b. Patient 2 Right face/chest pre-treatment

2000

1500

(mL) 1000

500 Volume

0 -18 -12 -6 0

c. Patient 2 whole body post-treatment 10000

9800

9600

9400 Volume (mL) 9200

9000 0 6 12 18

Figure 4.2 Plexiform neurofibroma volumes over time (months) pre- and post- treatment with imatinib (0=start therapy).

Patient 1 20

Symptom Score Patient 2

0 0 3 6 9 12

Figure 4.3 NF1 Symptoms Questionnaire Scores over time (months) on imatinib (0=start therapy).

0.8

0.6

0.4

Patient 1 LOWS score 0.2 Patient 2

0 0 3 6 9 12

Figure. 4.4 Linear Overall Wellbeing Scale (LOWS) scores over time (months) on imatinib (0=start therapy).

68 frequency of clinical symptoms higher than Patient 1, the former reported higher levels of overall wellbeing (LOWS scores), and both symptoms and wellbeing remained static over time. In contrast, results for Patient 1 indicated increased symptoms and decline in wellbeing during treatment.

Baseline SF36 results are shown on Table 4.2 along with Australian normative data for young adults, and results from a predominantly adult European hospital based NF1 population for comparison. Responses for Patients 1 and 2 were consistent with severe disease, reflecting the intended selection bias. Both reported limitations in physical functioning and pain along with significant impact on activities of daily living. Scores were also reduced for vitality and perceived general health, compared with the Australian young adult population. Social functioning was affected to a lesser degree, with both individuals showing resilience in terms of mental health factors, reporting no impact on activities of daily living due to emotional difficulties.

SF36 responses over time during treatment with imatinib are shown in Figure 4.5, with the eight domains clustered into physical and mental groups. At four months, improved scores were recorded for both physical functioning and activities of daily living (PhysFxn and LimPhysHlth, Figure 1a) for Patient 1, which may have related to other factors such as change in analgaesic treatment at that time. However pain responses remained the same. This improvement was not sustained. For the remaining six domains, responses were static over time or showed a decline in functioning. Similarly, for Patient 2, between baseline and ten months on treatment, responses across the eight domains showed static or declining functioning, in all except social functioning. The explanation for change in social functioning is unclear and likely related to other environmental factors for this individual. Pain was not improved in either patient.

Adverse Events Treatment was well tolerated, without dose modification for adverse effects in either case. Grade 1 hair loss (thinning of scalp hair) and oedema were recorded in Patient 2 which were not treatment limiting.

69 Table 4.2. Baseline SF36 responses for Patient 1 and 2 compared with Australian norms and hospital cohort of French NF1 patients

Physical Health Domains Mental Health Domains

Population Physical Role Pain General Vitality Social Role Mental Health

Functioning Phys Health** Health Energy/Fatigue Emotl Hlth*** Emtl Wellbeing

Patient 1 85 25 35 15 65 75 100 96

Patient 2 25 75 45 55 35 50 100 92

NF1 adults‡ 76.8 72.8 65.3 58.4 49.7 70.4 69.4 56.4 (SD) (26.4) (39.1) (29.6) (23.0) (21.3) (25.7) (39.4) (22.0) 75.2.5)

Aust Norm* 90.1 87.4 81.6 73.7 66.5 85.9 83.7 75.2 (SD) (25.2) (40.4) (30.3) (25.2) (25.2) (30.3) (45.4) (25.2)

‡ Wolkenstein et al. (N=171, 2<18 years)(148); *Australian normative values of 18-24 year olds, combined genders(147); **Problems with work or other daily activities as a result of physical health; ***Problems with work or other daily activities as a result of emotional health; Aust=Australian, Emtl=emotional, Hlth=health, Phys=physical.

70 a. Patient 1 Physical Domains b. Patient 1 Mental Domains

c. Patient 2 Physical Domains d. Patient 2 Mental Domains

Figure 4.5 SF36 domain scores for physical and mental health over time (months) during treatment with imatinib.

Long-term follow up Regarding long term follow up, both patients were treated prior to transition to adult services. For Patient 1, issues regarding medication supply complicated treatment at transition to adult services. One further MRI was available for Patient 1, eight months after cessation of imatinib, showing a small increase in cervical tumours (volumetric data not available). Phone follow up indicated no major functional change. Resection of selected cervical tumours was under consideration. At 12 months treatment Patient

71 2 experienced a rapid decline in motor strength associated with loss of independent ambulation (a wheelchair was required). Repeat spinal imaging demonstrated stable cervical cord compression with some cord oedema, little changed from previously. Imatinib was ceased due to the need for definitive surgical intervention. C1-C4 spinal laminectomy was performed plus debulking of cervical neurofibromas with good effect. Independent ambulation was regained, and sustained at 24 months post- surgery.

Additional children treated for PNF (outside the current protocol) Table 4.3 presents an overview of children in the Neurogenetics Clinic at The Children’s Hospital at Westmead treated with novel medications between 2009 and 2015.

Discussion Tumour Volume In the two patients closely followed in this study, stable tumour volumes were demonstrated in response to imatinib treatment. The primary outcome for efficacy based on full or partial radiologic response (tumour shrinkage) was not attained in either case. In one patient, stable disease contrasted with progressive pre-treatment disease, suggesting some efficacy. Interpretation of the stable result was difficult in the second patient due to a change in tumour measurement pre- and post-treatment. Tumour shrinkage was not demonstrated in either case. Although medication was well tolerated, secondary outcomes of clinical response based on patient reported symptoms and quality of life failed to indicate significant benefit in any of the measured outcomes.

These patients, both older adolescents, had severe disease. A high tumour load was present, with tumour volumes measured in Patient 2 being in excess of that measured in 171 individuals of all ages who participated in a study of patterns of PNF growth using whole body MRI (107). In this cohort median volume was 86.4ml, ranging from 5.2 to 5878.5mL (107). Such large tumour burden is more likely in patients with NF1 deletions (>3,000ml) (150). Baseline tumour growth rates in our patients showed progressive disease, in contrast with the median growth rate of 3.7% per year (range

72 Table 4.3 Additional NF1 patients with complex symptomatic PNFs treated at the Children’s Hospital at Westmead since 2009

Patient Age NF1 Genotype Indication PNF Location Volume Procedures (N) Agent Study Type Duration Outcome Side effects (mL)

3 15y NA Pain (hips) Hip/Gluteus NA No Imatinib Compassionate 6m Unchanged imaging Nil maximus Use and clinical status Limited mobility Para-pharyngeal Cosmetic deformity 98.33

4 5m Hz truncating Airway obstruction Neck/ 51.65‡ Biopsy neck Imatinib Compassionate 7m Progressive disease Nil mutation c.147C>G Tracheostomy Mediastinal/ lesions/debulking Use (p.Tyr49*) Nocturnal ventilation Thoracic PNF mediastinal lesions; Paternal Pericardial effusion Stent L main bronchus; 30m Tracheostomy Trametinib Compassionate 36m Stable clinical Itch (4) Use ongoing disease

5 18y NA Pain (buttocks/legs) T-L spine / Gluteus 690.09 Debulking sciatic Trametinib International 8m Pending Acneiform maximus nerves Clinical Trial Discontinued rash Peripheral nerves (2) Patient choice (rash)

6 8y c.[4270-2A>G] Pain;Daily analgaesia Paraspinal (T-L)/ 422.21 No Trametinib International 18m Clinical response Coarsening Paternal Anxiety Gluteus maximus Clinical Trial ongoing scalp hair

7 5y Paternally Cosmetic disfigurement Periorbital PNF 26.19 No Trametinib International 12m Clinical response Folliculitis x2; inherited NF1 Threatening visual axis Clinical Trial ongoing Other skin Infection x1 8 10y NA Unilateral leg paresis c- Multilevel spinal 2010.7 No Trametinib Compassionate 27m Radiologic response Eczematoid spine* with cord disease; discrete Use ongoing Clinically stable rash compression c-spine tumours

* c-spine=cervical spine; NA=not available; Hz=heterozygous, m=months, y=years; ‡ underestimate of baseline volume prior to treatment reflecting most recent NFtumormetrics data (2012/2013); NA-difficult to measure.

73 13.4% to 111.1%) during follow up of 2.2 years (range 1.1-4.9 years, N=171) (107). Both patients experienced significant daily pain treated with analgaesics, and narcotics in one case. This contrasts with 59 children selected for 7 medical treatment trials at NIH between 1996-2007, where 53% experienced pain, and 5% required daily narcotic use. In a broader patient group with spinal and paraspinal neurofibromas (71% younger than 18 years), half of patients experienced pain, with a quarter reporting daily symptoms(127).

The CHW approach to treatment with imatinib shares a number of features, and some differences with the largest series of treated patients published to date by Robertson et al(68). In Robertson’s study, patients were not selected based on static or progressive growth, as pre-treatment growth rates were not measured. In addition, patient reported outcomes were not included, with limited subjective data regarding functional outcomes only. Thirty-six patients with clinically significant PNFs were treated with imatinib including 47% children and adolescents (median age 13 years, range 3-52 years). Of 23 evaluable patients treated for at least 6 months, six (26%) had a 20% or more decrease in volume of one or more PNFs. Interestingly, a trend toward larger tumours showing reduced response was reported. It may be that optimal response with any systemic therapy will be achieved in smaller actively growing lesions, a hypothesis to be tested in future studies. Subjective symptomatic improvement was reported in 30% of patients (7/23) including reduction in pain, improved motor functioning and improved bladder functioning such that catheterization was no longer required. The authors recognized the need to quantify functional responses objectively, and to formally include patient- reported outcomes, leading to development of recommendations to enhance future study design (151, 152).

Patient-Reported Outcomes The inclusion of patient-reported outcomes in response evaluation for our patients provided evidence regarding clinical response in addition to radiologic response. However, determining the clinical meaningfulness of changes in scores is challenging. Whilst the NF1 questionnaire has not been validated in a large group of patients utilizing comparisons with comparable established tools, the trends observed over time paralleled results of SF36 responses in our patients. This questionnaire may be helpful for monitoring clinical status over time in other complex NF1 patients, and could be further

74 assessed with a view to formal validation in future.

The Linear Overall Wellbeing Scale generally mirrored results from other assessment tools, without providing additional detail. A simple overview measure such as this is most appropriate in populations with limited capacity to complete more detailed assessments. More comprehensive scales would be preferable for future use in the NF1 population. For the purpose of generalizability and comparison with treatment results at other centres, future studies at our site will include tools for assessing pain and other functional outcomes such as the Pain Interference Index (for ages 6-24 years) and the Patient-Reported Outcome Measurement Information System (PROMIS) Physical Functioning Scale (for ages ≥5 years). These scales have been recommended by the Response Evaluation in Neurofibromatosis and Schwannomatosis (REiNs) collaboration, subsequent to the conduct of this study (152).

Regarding quality of life assessment, the SF36 is a validated tool for use in adults. It has however, been utilized in other populations with individuals younger than 18 years, due to the unavailability of other appropriate tools in the past(148). It is likely that responses for younger patients would be conservatively represented here for physical functioning as these scores typically decline with increasing age in the normal population, although small increases occur in several domains of the mental health cluster with increasing age.

SF36 domains deviating from population norms in a hospital-based French cohort of NF1 patients included physical functioning, bodily pain, general health perception and vitality. Similar domains were affected for our treated patients with severe disease. Their responses showed greater functional impact in several domains (including physical functioning, pain and general health perception) than the French cohort, which included patients of all ages. Despite this, both patients scored highly in regard to perception of social functioning and emotional wellbeing/mental health factors. For Patient 2 this was somewhat surprising considering others have identified a strong association between reduced emotional wellbeing and a high burden of skin disease and deformity(148).

The protocol for this study identified both the PedsQL(153) and Impact of Pediatric Illness Scale(154) as possible tools for use in children. Difficulties were experienced in

75 accessing the former. The Pediatric Illness Scale evaluates CNS symptoms, medical/physical status, adaptive behaviour, and psychological/emotional functioning given to both parents/caregivers and children older than six years. However the SF36 was used in preference here due to the older age of the patients included, and our increased familiarity with this tool. Quality of life data derived using the Impact of Pediatric Illness Scale are now available from other populations of children with NF1 treated for PNF, establishing important comparative data for future studies(97, 98). In addition, seven other quality of life studies for children with NF1, using different measurement tools, have recently been reviewed (155). Although these all showed reduction in quality of life, improved standardization of measurement is needed for future studies (155).

Additional children treated for PNF (outside the current protocol) As shown in Table 4.3, subsequently treated children are younger, with smaller, actively growing lesions, representing examples from the high-risk groups now followed closely with clinical and radiologic surveillance from an early age. One younger adolescent (aged 15 years) received imatinib prior to the two patients described in detail here. Treatment was indicated for a large plexiform neurofibroma eroding the hip joint, causing significant pain and limiting mobililty. Symptoms failed to improve significantly, and the diffusely infiltrative nature of the tumor made accurate measurement difficult. Radiologic response in a second measurable para-pharyngeal plexiform neurofibroma failed to show tumour shrinkage(156).

Based on reports of medication tolerability in younger children (157), imatinib was also offered to an infant with significant airway involvement followed by clinical and radiological progression after six months, leading to cessation of treatment. Around this time, data from in vitro studies using MEK inhibitors showed promise. In mouse and human cells, and in vivo mouse models, shrinkage of plexiform tumours was observed in a majority of treated animals along with prolonged survival of animals with MPNST(158, 159). On this basis, we prescribed the MEK inhibitor Trametinib, which has a favourable side effect profile (160), and was available in Australia. This resulted in clinical improvement, including reduction in ventilatory support, with sustained improvement over 36 months. Radiologic response has been difficult to demonstrate

76 based on accepted volumetric criteria. This is in part due to suboptimal imaging associated with risk management of a tenuous airway during anaesthesia. Another patient subsequently treated with trametinib on a compassionate basis has had a reduction in the size of cervical neurofibromas. Both have tolerated treatment well.

Three additional children have now been enrolled in a multi-centre international clinical trial with encouraging clinical progress, including improvements in functional status due to reduction in pain. One patient elected to cease treatment with trametinib due to acneiform skin rash, a recognized adverse effect. Phase 1 results recently published described exciting observations of MEK inhibition using selumetinib in children with plexiform neurofibromas. Tolerability during a median of 30 cycles (range 6-56) was established, with 71% of children (17/24) showing partial radiologic response to treatment (≥20% reduction in tumour volume) together with anecdotal evidence of improved pain, disfigurement and motor functioning (70).

Limitations and Future Directions Limitations of this study include the small number of patients involved, and short duration of treatment and follow up. Data were not available for all time points planned. However, the detailed approach to assessment of outcomes provided helpful information regarding the limited potency of imatinib for both radiologic and clinical response. Other authors have highlighted the need to provide an adequate treatment trial in terms of duration of therapy, recommending 12 months as a minimum (68). It could be argued that additional benefits may have been seen in these individuals with a longer course of treatment. Given the limited data available in this study, interpretation has been made from simple graphical presentation rather than statistical analysis, which would be necessary to assess confidence in observed differences in a larger dataset. Despite these limitations, this study helped to establish effective surveillance of high risk PNFs in our paediatric population of NF1, along with principles of methodology in medical treatment trials for this indication, including recognition of radiologic and patient reported outcomes. Overall, we gained invaluable experience in the selection and monitoring of patients for compassionate treatment of these complex tumours, and this has led to our inclusion as a site in international clinical trials.

77 Although not included in this study protocol, other functional outcomes such as 10 metre-walking tests were monitored over time in these patients. This measure may be helpful in certain circumstances such as in motor decompensation due to spinal cord compression, as described in Patient 2. Objective measures of muscle strength using dynamometry may also have a role as an outcome measure.

Moving forward, the potential utility of tissue biomarkers to assist in interpretation of variable responses to treatment, and in the longer term to direct individualized patient therapy, is also recognized. The CHW biobank includes tumour samples and serum samples for selected individuals, which may be helpful in this regard, and represents a resource to maintain and expand in future.

Conclusion In conclusion, this chapter highlights many of the significant challenges inherent in managing individuals with NF1-associated PNFs. The extensive tumour burden and associated morbidity that can occur by late adolescence is sobering. It is hoped that early treatment of potentially complicated tumours will prevent progession and associated morbidity in the near future. Assessing radiologic response in complex tumours is difficult, even in established NF centres. Because of the complexity of tumour measurement, selected centres of excellence calibrated for accuracy and reproducibility of volumetric analysis are essential to ensure integrity of data for radiologic response evaluation. Furthermore, significant advances have been made in recent years through the work of the REiNS collaboration, to improve the methodology used in clinical trials, from radiologic to functional outcomes and quality of life in patients with PNFs (25). The approach utilized in this study represents part of the evolution of clinical research and clinical care for children with NF1 complicated by complex PNFs.

SECTION 2:

NEUROFIBROMATOSIS TYPE 2

79 CHAPTER 5. NEUROFIBROMATOSIS TYPE 2: PRESENTATION, MAJOR

COMPLICATIONS AND MANAGEMENT, WITH A FOCUS ON THE PAEDIATRIC

AGE GROUP.

Introduction Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder caused by mutations to the NF2 tumour suppressor gene, characterised by multiple non-malignant nervous system tumours, including schwannomas, meningiomas, ependymomas and gliomas, with bilateral vestibular schwannomas (VS) being a classical feature. Ocular and cutaneous manifestations also occur. Incidence is estimated at 1 in 33,000-40,000 and prevalence 1 in 100,000 (161). The condition is typically diagnosed at age 20-30 years, but features are often present for many years before the diagnosis is made in both sporadic cases and in those with a family history (162-164). About 10% of patients present before the age of 10 years, and 18% before the age of 15 years, with a greater diversity of clinical problems than seen in adults, and often with increased severity (165). In this review we explore the presentation and clinical course of NF2 with particular reference to children and adolescents, and a view to improving outcomes for all affected individuals.

Diagnostic Criteria The diagnosis of NF2 based on clinical criteria has been refined over time, reflecting the typical presentation of adults with symptoms of vestibular schwannoma (Table 5.1) (11, 166, 167). However, these criteria are less helpful in children who frequently present with other symptoms and signs of NF2, and for whom vestibular tumours may be too small to appreciate on initial neuroimaging. Examination of the skin and eyes often yields important diagnostic clues during childhood, and as such is of fundamental importance in suspected cases. Parents of children suspected of having NF2 should also be assessed carefully for symptoms and signs of NF2.

Time to diagnosis is highly variable and is often prolonged despite symptoms presenting in childhood. A recent report cited time to diagnosis in subgroups of adults and children

80 Table 5.1 Clinical diagnostic criteria for NF2

Primary Finding Additional features needed for diagnosis

Bilateral vestibular schwannomas None needed

First degree relative with NF2 Unilateral vestibular schwannoma OR Any two other NF2-associated lesions: Meningioma, schwannoma, glioma, neurofibroma, cataract

Unilateral vestibular schwannoma Any two other NF2-associated lesions: Meningioma, schwannoma, glioma, neurofibroma, cataract

Multiple meningiomas Unilateral vestibular schwannoma OR Any two other NF2-associated lesions: Schwannoma, glioma, neurofibroma, cataract

Modified from (166, 167).

at 5 years and 8 years respectively, with the delay ranging up to 21 years for adults and up to 36 years for children (168).

Genetics The NF2 gene is located on chromosome band 22q12, and encodes a protein known as merlin (a moesin-ezrin-radixin-like protein) or schwannomin (14, 169). Merlin is important in anchorage of the cytoskeleton to the cell membrane, the organization of cell membrane proteins and interaction with cytosolic proteins. The pathways involved are required for cell growth, protein translation and cellular proliferation. The absence of normal merlin is associated with a predisposition to tumour formation (170). A detailed description of the complex cellular and molecular neurobiology of merlin is outside the scope of this article, but has been reviewed by others (167, 171).

In most NF2 tumours, biallelic inactivating mutations are found. The gene may be inactivated by mutation, silencing or allelic loss (172, 173).

NF2 has almost complete penetrance by the age of 60 (161) . About fifty percent of patients are the first affected in their family, and are described as having de novo mutations. The other fifty percent are due to sporadic mutations (161), which may occur

81 in parental germline cells (prezygotic), or in postzygotic cells in which case mosaicism may result, such that only a proportion of cells carry the mutation. It is estimated that 25% of sporadic mutations are mosaic (174). The transmission rate depends on the degree of mosaicism. For children of patients with a de novo mutation, the transmission rate is 50%, because all the child’s cells contain the mutation. However, the transmission rate may be lower in de novo patients, as germ cells may not contain the mutation(175).

Identification of a mutation in the NF2 gene is possible in over 90% of familial cases (167), and 80-85% of individuals with sporadic mutations (176), confirming the diagnosis when present in both tumour and blood (177). In mutation-negative individuals, confirmation of the clinical diagnosis is possible through careful follow up over time.

In children presenting early with a more severe clinical course, mosaicism is less likely and consequently the mutation detection rate is higher. One study exploring the utility of mutation testing to screen for NF2 in patients presenting with unilateral VS showed that this is justified in those presenting <20 years of age. 83% of patients presenting under the age of 20 with a unilateral VS were found to have a detectable NF2 mutation compared to 7.7% when looking at all ages (178).

In children of a parent with NF2, identification of a mutation has a major impact on the further screening of that individual (179). In sporadic cases, failure to identify a mutation does not obviate the need for ongoing surveillance, due to the phenomenon of mosaicism, or possibly presence of mutations in intronic regions, promotor mutations or large multiexonic deletions (164).

Genotype-phenotype correlation Missense mutations usually cause mild symptoms and signs of NF2 (180). Nonsense/frameshift mutations produce a truncated protein, and tend to be associated with a more severe phenotype, earlier onset, more rapid disease progression and higher tumour burden with more spinal and intracranial tumours in addition to VS (166, 181). Mutations in the 3’ half of the NF2 gene are associated with lower risk of meningioma

82 than mutations in the 5’ half of the gene with a cumulative risk of cranial meningioma to age 50 years highest at 81% for exons 4-6, and lowest at 28% for exons 14-15(182). Clinical heterogeneity amongst established NF2 families is now recognised (i.e those in whom mosaicism is unlikely), suggesting that NF2 gene expression may be affected by other environmental or epigenetic factors (183).

In some cases, NF2 can occur in children with additional features including dysmorphism, intellectual disability and congenital abnormalities, due to a large cytogenetically visible deletion including the NF2 and other genes, which may be identified on karyotype or chromosomal microarray(184).

NF2 Associated Tumours Tumours occur in intracranial and spinal regions as well as on peripheral nerves, causing variable symptoms and signs depending on their location. Within the intracranial compartment, tumours can cause deafness, blindness, headaches, seizures, gait abnormalities and a range of other focal deficits. Spinal cord tumours occur in between 60 to 90% of patients (181, 185, 186), causing sensory and motor dysfunction including paralysis, and bladder and bowel dysfunction. Pain may be a feature of central or peripheral tumours, and is positively associated with tumour burden (187).

Spinal tumours occur both within the cord (intramedullary) and within the canal on exiting nerve roots or originating from the meningeal covering of the cord (extramedullary). There appears to be no predilection for a particular location, multiple tumours being common in cervical, thoracic and lumbar regions. One study examining spinal tumours found that, of the 63% of NF2 patients affected (N=31/49), 53% had intramedullary, 55% extramedullary tumours and 45% had at least one of each tumour type (181). Multiple tumours commonly occur in a single patient.

The risk of malignant transformation of tumours in individuals with NF2 is higher than in the general population. Among 1348 patients across North American and European centres, 9 cases of malignant nervous system tumours were identified, equivalent to 725 per 105 population compared with 1.13 per 105 in the general population. Radiation associated malignant transformation was estimated to occur in 4717 per 105 in the NF2

83 population (188). Some authors have estimated exposure to radiotherapy increases the risk 10-fold (188, 189).

Schwannomas Bilateral vestibular schwannomas are the characteristic tumour of NF2, affecting 95% of all patients, causing tinnitus, vertigo, hearing loss, and brain stem compression (Figure 5.1b-f). They tend to form on the inferior vestibular branch of the 8th cranial nerve. In the general population with VS, 7% of individuals have NF2 (190). Increased morbidity is associated with these tumours among individuals with NF2 compared to patients with sporadic tumours (isolated vestibular schwannomas associated with mutation in the NF2 gene in tumour tissue only), in part due to an increased growth rate of tumours in NF2 (191). There is significant risk that an NF2 patient with a unilateral VS will develop bilateral VS, with a mean delay of 6.5 years reported in one study. In the paediatric age group, the time to development of the second VS is shorter; mean delay of 3.25 years for radiological evidence of VS and 7.3 years for hearing loss becoming bilateral (192).

Schwannomas occur on other cranial nerves, the most common being unilateral or bilateral involvement of the trigeminal nerve (186), also around the spinal cord and exiting spinal nerve roots, along peripheral nerves, and in the skin. In one series, spinal and intracranial schwannomas occurred nearly as frequently as VSs (163).

Meningiomas Meningiomas are the second most common tumour type in NF2 (Figure 5.1f), occurring throughout the central nervous system in 50-75% of individuals, often with multiple tumours (162, 166, 193, 194). Whilst some meningiomas remain static and require no active treatment, NF2-associated meningiomas tend to be higher grade than sporadic tumours (195). Some meningiomas have been found to grow more rapidly than schwannomas, although growth rates are variable for both tumour types (177). Female sex and younger age at NF2 diagnosis have been associated with increased growth rate in one recent report (196).

While there is no specific site in which they form as commonly as VS, meningiomas usually occur around the spinal cord, supratentorially in the falx, and around the frontal,

Figure 5.1 NF2 associated tumours: cervical spinal ependymoma with associated syrinx in a 14 year old shown on sagittal T2 weighted MRI (a) and post-resection (b); bilateral vestibular schwannomas at age 14 years (b,e), and at 18 years (c,f) shown in T1 weighted MRI with gadolinium contrast (b-c) and T2 weighted images (e-f), larger on left (white arrows). Parasagittal meningioma also shown (f, black arrow).

temporal and parietal regions, including the optic nerve sheath.(177). Optic nerve sheath meningiomas may be bilateral, occur early in life and can be associated with complete vision loss (165, 197, 198).

Schwannomas and meningiomas occur infrequently during childhood, having an estimated association with NF2 in at least 10-18% of cases. Constitutional NF2 is now acknowledged as the most frequent cause of meningioma presenting in childhood (199). NF2 has been diagnosed in 28% of children with optic nerve sheath meningioma (197, 198).

85 Gliomas Glial cell tumours (ependymomas and astrocytomas) are often detected radiographically, but cause symptoms less frequently than other tumour types. They tend to affect the lower brain stem and upper cervical cord more often than other locations(165). The prevalence of intracranial astrocytomas and ependymomas in NF2 varies between 1.6- 4.1% and 2.5-6% respectively (200); the frequency of both tumour types is much higher (24%) in the paediatric NF2 population (179).

About 30% of NF2 associated spinal tumours are intramedullary(201), and are most likely to be ependymomas (Figure 5.1a,d). These tumours occur in childhood but may be clinically silent for many years. A series of 12 patients, aged between 10 to 56 years, with spinal ependymomas was reported recently (202). Ten of twelve patients presented with gait abnormality, eight with paresis/paralysis, four with pain, and two patients experienced sensory deficits and limb ataxia. Based on detailed pathology studies, the authors concluded that NF2 associated gliomas in the spinal region are almost exclusively ependymomas (202). These tumous can be surgically resected without significant residual deficits. They are of low malignant potential.

Manifestations of NF2 Affecting the Skin, Eyes, and Peripheral Nerves Cutaneous findings Café au lait macules (CALM) are more prevalent than in the general population and are often present in children with NF2 (Figure 5.2a), but rarely reach the size or numbers seen in NF1 patients (165, 203, 204). They tend to be paler and have more irregular margins compared to those of NF1 (179). Hypopigmented areas can also occur (204). CALM are often present early in childhood, followed by increase in number and size of skin tumours over time (205).

Whilst about 68% of individuals have characteristic cutaneous features of NF2, these constitute the first recognisable symptoms or signs in up to 25% of cases (204). Three types of skin tumours occur in NF2; NF2 plaques, nodular schwannomas and neurofibromas (Figure 5.2 d,f). Flat dermal NF2 plaques are cutaneous schwannomas appearing as well defined, slightly raised hyperpigmented lesions, often with excess hair, typically less than 2cm in diameter (204). During childhood, these can occur on the

Figure 5.2 Cutaneous and ophthalmologic findings of NF1 (a-b) and NF2 (c-f): Café au lait macules (a), pigmented cutaneous neurofibroma in NF1 with numerous other subtle raised neurofibromas on the trunk of a 15 year old with NF1 (b). Posterior subcapsular cataract (c), optic atrophy in child with optic nerve sheath meningioma and epiretinal membrane (black arrow, e), NF2 plaque (d) and nodular schwannoma (f).

trunk (206) as commonly seen in adults, or on the upper and lower limbs, including hands and feet (179). Nodular schwannomas are well defined and usually spherical, occurring subcutaneously around peripheral nerves. There is no pigment change to the overlying skin which can be palpated as separate from the tumour (165). Neurofibromas,

87 although classically associated with NF1, can occur in NF2, but do not comprise the main tumour burden (177, 200).

A high burden of skin tumours is associated with increased severity of disease overall, with about 10% of individuals having greater than 10 tumours (165, 204).

Ophthalmologic findings Ophthalmologic abnormalities are present in the majority of NF2 patients, including cataracts (70-80%), retinal changes (20-44%), strabismus (12-50%), amblyopia (12%), optic nerve sheath meningiomas and other optic pathway tumours (10-27%), and extra- ocular movement abnormalities (10%) (168, 207-209). Optic nerve sheath meningiomas are the characteristic tumour of NF2, whereas optic pathway gliomas including the optic nerves and posterior optic pathway are more typical of NF1 (Figure 5.3) (103). Nystagmus may occur due to eye involvement, peripheral vestibular dysfunction, or posterior fossa tumours with brain stem compression. Corneal injury affects about 10% of NF2 patients with other ocular abnormalities, and in association with facial nerve weakness.

Most ocular changes are congenital in origin and specific to NF2, and as such have been highlighted as early diagnostic clues to NF2 in children (210). Cataracts are often bilateral, occurring as posterior subcapsular or peripheral cortical lens opacities (Figure 5.2c). These may not require removal, but reduce visual acuity in 10-20% of cases (168, 179, 207). Retinal abnormalities include combined pigment epithelial and retinal hamartomas. Epiretinal membranes (Figure 5.2e) are recognised in association with a severe phenotype of ocular involvement, which can lead to macular impairment and retinal detachment (162, 207, 211). The characteristic appearance of epiretinal membranes on ocular coherence tomography has been described recently (208, 211). Unfortunately, misdiagnosis of ophthalmologic complications of NF2 in early childhood (retinal hamartomas and optic nerve sheath meningiomas) as retinoblastoma has resulted in enucleation of the globe in a number of cases.

A recent study of 30 patients (60% children with onset NF2 symptoms ≤18years, 40% adults, onset >18 years) in a university ophthalmology department, documented more

Figure 5.3 Optic nerve sheath meningioma in a 7-year-old with NF2 (left side a, c) and optic nerve glioma in a 10-year-old with NF1 (right side b, d) shown on axial T1 weighted MRI (a non-contrast, b with contrast) and coronal T1 weighted images (c, d both with contrast).

frequent ophthalmologic abnormalities in the paediatric population (94%) compared with the adult population (67%) (168). While impairment in visual acuity has previously been estimated to affect over 30% of NF2 patients overall (208), this study documented significantly poorer visual outcomes for children, with only 14% having normal visual acuity at the end of similar periods of follow up compared to 78% of adults, due to increased incidence of cataracts, epiretinal membranes, and optic nerve sheath

89 meningiomas among children (168). The authors reported a significant correlation between younger age of onset and increased number of central nervous system tumours.

Peripheral neuropathy Peripheral nerve dysfunction can occur in NF2 without obvious focal tumour. Cranial nerve deficits are more frequent presenting signs in childhood than adulthood, occurring in forty percent of children in one study (eg. commonly facial palsy; strabismus due to third nerve palsy, swallowing impairment, tongue atrophy)(164). Children may also present with a mononeuropathy in the limbs, most commonly foot drop, in the absence of a focal brain stem, spinal cord or peripheral nerve tumour (10, 165). Marked wasting may be associated with the footdrop, and significant wasting can also be seen in the hands, most prominently in the thenar and hypothenar eminences(175).

The peripheral neuropathy associated with NF2 tends to be a mixed motor and sensory axonal neuropathy occurring in a glove and stocking distribution, with distal weakness, fasciculations and hypaesthesia (165, 212, 213). Pathologic studies have identified loss of both myelinated and unmyelinated nerve fibres, sometimes with an onion bulb appearance (212). Schwann cell and epineurial cell proliferation with entanglement of axons has been described, without formation of a discrete tumour (212, 213).

Investigations Audiology Hearing evaluation typically includes pure tone audiometry, speech intelligibility assessment and brainstem auditory evoked responses for clinical evaluation, with recommendations recently published regarding optimal outcomes for use in clinical trials (214).

Neuroimaging The best radiologic investigation of intracranial and spinal tumours is MRI with gadolinium contrast, including detailed views of the internal auditory canal (a minimum of 3mm slices in both axial and coronal planes for clinical evaluation) (177, 179). Volumetric approaches to tumour measurement provide the most sensitive assessment of tumour size for vestibular schwannomas both for monitoring disease progression and

90 response to treatment (22, 124, 215). Whole body MRI to assess total tumour burden may play an increasing role in management of patients with NF2 (126). A whole body approach allows identification of symptomatic or potentially symptomatic lesions. Radiologic response to systemic therapy may ideally include multiple target tumours in future reflecting the complexity and multiplicity of tumours and clinical symptoms in NF2. However, the role of whole body MRI is not clearly established as yet.

Other Investigations Fluoro-deoxy-glucose positron emission tomography (FDG-PET) may have a role in selected cases where malignant transformation is suspected. Depending on the clinical context, a range of other investigations may be needed to evaluate new symptoms or deficits, including nerve conduction studies, electroencephalography, and other functional studies.

Clinical Course While individuals with NF2 typically experience progressive symptoms and signs of disease, the clinical course varies between individuals, depending on age of onset, genotype, tumour burden, complications and management. Saltatory growth (alternating periods of growth and quiescence) is most common for NF2 associated tumours, although linear growth and exponential growth do occur (196). Age of onset and age of diagnosis are the two most important factors in predicting disease severity (180, 183). The presence of meningiomas and treatment in non-specialist centres have also been associated with risk of earlier mortality (180).

Natural history studies of vestibular schwannomas, have demonstrated progressive disease over time, though rate of progression varies between tumours, and change in hearing is not necessarily directly correlated with tumour growth (216, 217). Significant tumour progression (defined as ≥20% increase in tumour volume) of 31% at 1 year and 79% at 3 years has been reported in 120 patients (200 tumours), associated with cumulative hearing decline of 16% over 3 years (defined as decrease in word recognition score exceeding the 95% critical difference compared with baseline) (218).

The natural history of 287 cranial meningiomas in 74 patients with NF2 was reported

91 recently, with a mean follow up of 9 years. About one quarter of the group were aged <18 years at the time of diagnosis. Sixty nine percent of patients had at least a single operation for VS, 23% for spinal tumours (194). Significant growth of at least one meningioma during one year (≥20% increase in volume) was found in 28% of patients (7.3% of 267 tumours). 46% required surgical treatment for meningioma, for variable indications including epilepsy, intracranial hypertension and specific neurologic deficits (194).

Limited data are available regarding longevity in NF2. However, 38% survival at 20 years from diagnosis, has been estimated for the population as a whole (219).

Clinical Presentation and Natural History of Paediatric Cases Presentation of NF2 in the paediatric age group is often unrecognised. In a group of 368 individuals reported previously, 153 (42%) had onset of symptoms between 1-19 years of age (180). While adults typically present with hearing loss and tinnitus as a consequence of vestibular schwannomas, these symptoms often follow other presenting features in the paediatric population. In fact, VSs account for only15-30% of presenting symptoms in paediatric cases (10). Symptoms of VS have been delayed by over 40 years in some patients presenting in childhood (220). Children are more likely to present with visual symptoms, spinal cord compression or neurologic symptoms from other intracranial tumours (162, 164, 203, 221). Furthermore, where both VS and spinal tumours are present, children are more likely to be symptomatic from spinal tumours than from VS (163). Astute clinicians may suspect the diagnosis of NF2 based on cutaneous or ophthalmologic manifestations alone in a proportion of children.

In five paediatric case series (total N=109), mean age at first presentation varied between 5.5-7.0 years, whilst mean age at diagnosis varied from 8.8 to 14.9 years (10, 162, 164, 179, 221). The presenting features of these children are summarised in Table 5.2.

Tumour burden and associated morbidity and mortality among children are typically higher than in the adult NF2 population. Among 12 children from a North American

92 Table 5.2 Presenting symptoms in NF2 populations including paediatric patients

Age Group Hearing Tinnitus Vertigo/ Muscle Facial Seizures Pain Headache Visual Sensory Footdrop Cutaneous Other Ref. loss loss of weakness nerve Involvement symptoms balance wasting palsy All Ages 44 10 8 12 - 8 4 - 1 2 - NI 11 (165) (2-52 yrs) Pre-sympt. N=100

All Ages 19 7 2 3 - 2 3 2 10 - - 8 b 2 (3.4%) c (203) (7-71 yrs) (30%) (11%) (3.4%) (4%) (3.4%) (4%) (3.4%) (16.4%)a (13%) 5 (8%) N=63 Pre-sympt.

10 yrs 2 - - - 3 3 - 1 1 - 1 NI - (165) (18%) (27%) (27%) (9%) (9%) (9%) N=11

<16yrs 1 - - 2 - 1 2 - 8 d 5 e - (162, 206) N=18 (5%) (9%) (5%) (9%) (44%) (28%)

f g h ≤10 yrs 4 1 - 3 5 8 - 2 4 1 1 1 1 (10) N=30 (13.5%) (10%) (17%) (27%) (6%) (13.5%) (3%) (3%) (3%) (3%) Weight loss (glioma)

i ≤17yrs 3 1 - 2 2 - - - 1 - - NI 3 (164) N=12 (25%) (8.3%) (16.5%) (16.5%) (8.3%) (25%)

j k ≤ 15yrs 1 2 - 6 1 1 1 - 7 - - 8 CALM 3 (179) N=24 (4%) (8%) (25%) (4%) (4%) (4%) (29%) (33%) (12.5%) 3 tumours (12.5%)

<17yrs 5 - - - - See See - 3 - See other 5 b (+1 CALM) 5 l+ 6m (221) N=25 (20%) other other (12%) (24%) (20% + 24%)

a Ocular cause of vision loss (N=7), CNS tumour (N=2), diplopia (N=1); b painful or growing skin tumours; c personality change and dysphagia; d cataracts (N=3), oculomotor nerve (N=2), diplopia, epiretinal hamartoma, epiretinal membrane (N=1); e oculomotor nerve and skin (N=1); f spinal schwannomas (N=2), neuropathy (N=1); g presumed secondary to vestibular schwannoma; h plus nystagmus due to retinal hamartoma (N=1); i swallowing difficulty, foot eversion, nystagmus; j strabismus (N=3), amblyopia and strabismus (N=2), cataract (N=1), amblyopia (N=1), pigmentary retinal hyperplasia (N=1); k ptosis (N=2); voice changes/hiccups (N=1); l gait disturbance, leg or neck pain, footdrop due to peripheral nerve sheath or intradural-extramedullary tumour; m seizure, abdominal pain, incidental finding on chest x-ray, hoarseness (N=2); NI=not included -skin lumps and cataracts excluded in [5] as usually asymptomatic; skin lumps and amblyopia (non-specific) not included [4]; CALM= café au lait macules, pre-sympt=pre-symptomatic, Ref=reference.

93 tertiary NF treatment centre (164), hearing loss associated with VS was present by age 18y in 75% of patients. Seven children underwent surgical treatment for VS at an average age of 10 years, with immediate postoperative hearing loss in 4 cases. Progressive hearing loss occurred in all patients over time.

All children had other intracranial tumours, including 83% schwannomas, and 75% meningiomas; 75% also had spinal tumours. Only two patients were not treated surgically during childhood. One child had undergone five procedures and one received radiation therapy for progressive orbital meningioma. Outcomes were assessed across four domains – hearing, vision, ambulation and school performance. By 18 years of age, 83% of patients had visual impairment, 75% had hearing loss (bilateral in 2 patients). One patient was paraparetic, 2 others had difficulties with ambulation. 25% were functioning below age expectation at school, attributable to physical impairments and frequent hospitalization rather than baseline intellectual disability. Two children had impairments in all four domains. The authors highlighted significant morbidity despite active surveillance in familial cases and early surgical intervention (164).

In 2005, Ruggieri et al (179) described 24 individuals aged between 4 to 22 years followed at a European centre. Nineteen were ≤10 years old at the time of diagnosis, 22 were diagnosed aged ≤ 18 years. Bilateral vestibular schwannomas were present in 75% patients, with unilateral vestibular tumours in 16%. Other intracranial tumours included meningiomas (66% patients), astrocytomas (25%), ependymomas (25%), and other cranial nerve tumours (40%). Brainstem tumours were associated with a poor prognosis. Twenty one individuals had spinal tumours with successful resection achieved in 4 of 21 children with extradural lesions, and 3 with intradural tumours. Surgical treatment had been provided for 16 of 24 patients. 50% suffered significant morbidity during childhood, including 2 children who did not survive beyond 16 years of age (179).

Other case reports have documented early mortality associated with NF2, including a patient presenting at age 13 years with multiple craniospinal tumours, who died four years later despite multimodal treatment including surgery and chemotherapy (222).

94 Management Patients are best managed in tertiary centres by a well-resourced multidisciplinary specialist team experienced in dealing with the multiple complications associated with NF2 (180). Specialties involved may include neurology, genetics, ophthalmology, audiology, dermatology, radiology, neurosurgery, otolaryngology, medical and radiation oncology, clinical nurse consultants, allied health staff and psychologists.

Follow up of Children with Suspected NF2 Children with suspected NF2 require ongoing follow up to clarify the diagnosis over time; this may be based on the development of additional clinical features, and/or on genetic testing to identify NF2 mutations in blood and tumour (Table 5.3).

Molecular genetic testing is recommended for children of affected parents, recognising that clinical features may be insufficient to meet diagnostic criteria for NF2 until later in life. Leukocyte DNA from blood is usually tested in children of parents with NF2 (Table 5.3). Alongside genetic testing, baseline skin, neurology and ophthalmology (including slit-lamp) assessments are required, with annual clinical reviews thereafter. Hearing assessment and craniospinal MRI should occur from 10 years of age, unless clinical suspicion mandates earlier assessment (103).

In suspected sporadic cases, genetic testing is first performed on tumour DNA, with a view to identifying NF2 mutations on both alleles. This is followed by testing of leukocyte DNA to establish which mutation is constitutional and which is somatic (present only in the tumour). Failure to detect a mutation in blood may occur due to mosaicism, mutations located in intronic or promotor regions, or due to large multiexonic deletions (164). This can occur in patients presenting with unilateral vestibular schwannoma. Additional features of NF2 may be identifiable over time in a proportion of patients. Therefore, careful multimodal follow up is indicated (outlined in Table 5.3) to identify and treat complications early. Annual MRI scans are recommended from the age of 10 years (103, 166). Only when mutation in blood is negative, and two NF2 mutations are identified in tumour, is the diagnosis of constitutional NF2 unlikely (223).

95 Table 5.3 Recommended follow up for children at risk of having NF2 Child of affected parents Child with suspected NF2 (50% risk) (schwannoma, meningioma, skin features*) Baseline Birth – ocular, skin, Ocular, skin, neurological exam Assessment neurological + formal Audiology ophthalmology exam during early years Full craniospinal MRI

DNA analysis Pre-symptomatic diagnosis if Mutation analysis (blood and familial mutation known tumour)

Mutation found in blood: No mutation in blood: NF2 not NF2 carrier à follow up excludedàfollow up

Mutation not found in blood: No mutation in blood, 2 mutations NF2 excluded à no follow in tumour: up NF2 excluded **à infrequent follow up

Follow up 2-10 years of age: 2-10 years: Clinicial Annual ocular, skin, Annual ocular, skin, neurological neurological Ophthalmology, audiology Formal ophthalmology assessment if symptomatic >10 years of age: 10-30 years of age: As above + neuroimaging if not As above + audiology already indicated on clinical grounds

Neuroimaging <10 years of age: As clinically indicated > 10 years of age: Baseline craniospinal MRI or >10 years: At any stage based on clinical Repeat craniospinal MRI suspicion Then annual cranial MRI Tumour à follow up as suspected NF2 Spinal tumours present: No tumour à cranial MRI à annual spinal MRI every 2 years to age 20 years, then every 3 years.

*Fewer than 6 café au lait macules ie. not fulfilling criteria for NF1, or skin lumps; ** Other than small risk of mosaicism; modified from (179, 223).

96 Surveillance and Secondary Prevention in Confirmed NF2 Most individuals diagnosed with NF2 should be followed with a minimum of annual clinical evaluation and investigations, with increased frequency in the presence of significant complications (Table 5.4). Some adults with mild disease presenting in later life, may be managed with less frequent assessments.

Table 5.4 Recommended follow up for confirmed cases of NF2 Frequency

Clinical examination Neurologic examination Annual Skin examination Annual Ophthalmologic examination Annual Audiologic examination 6-12 monthly** Pure tone audiometry Speech recognition BAER*

Neuroimaging – contrast enhanced MRI Brain with IAMs 6-12 monthly** Spine 6-12 monthly**

Psychosocial Support Assess employment/school/family Annual Functioning

Genetic Counselling At diagnosis then at any stage

* BAER= brainstem auditory evoked response; ** frequency of follow up is dependent on age and disease burden. Modified from references (103, 162, 166, 167, 223, 224).

Medical management Significant effort has been invested in developing medical treatments for NF2 (100, 135, 225, 226) and appropriate clinical trial protocols in recent years, with a major focus on symptomatic, progressive vestibular schwannomas (23, 219). The most effective agent to date inhibits vascular endothelial derived growth factor (VEGF), which has a central role in angiogenesis for NF2 schwannomas (225). Anti-VEGF monoclonal antibodies such as bevacizumab (administered as a fortnightly intravenous infusion) provide a beneficial effect in treatment of vestibular

97 schwannomas including tumour shrinkage and hearing improvement in a proportion of patients (37, 227). The largest series reported to date included 31 patients aged between 12-73 years (median 26 years) with progressive vestibular schwannomas showing a median of 64% volume increase during 12 months prior to treatment. Tumour shrinkage (≥20% volume) was documented for 55% (17/31) patients, constituting radiographic response, while 57% (13/17) patients experienced hearing improvement based on a statistically significant increase in word recognition score. Both radiographic and hearing improvements were sustained for up to 1 year in about 90% of patients, with stable to improved status in 61% and 54% for hearing and tumour volumes respectively after 3 years (228). Limited efficacy in slowing progression of meningiomas has also been documented (226, 229). Although progressive vestibular schwannomas remain the primary indication for treatment, bevacizumab should also be considered for other progressive symptomatic NF2 associated tumours. Symptomatic benefit was recently reported in a series of 8 patients with spinal ependymomas, with radiologic response demonstrated in 5 cases based on a >20% reduction in linear measurements(230).

Lapatinib (available as an oral tablet) targets the epidermal growth factor receptor (EGFR/Erb2 inhibitor), and had some effect on vestibular schwannomas in a single institution phase II study (21 patients, 4 aged <18 years) (36). Radiographic response (≥ 15% tumour volume reduction), occurred in 4 of 17 evaluable patients (23.5%), varying from 15.7 to 23.9% volume reduction over a median of 4.5 months. Hearing response (defined as ≥10dB improvement in pure tone average or statistically significant improvement in word recognition score) was recorded in 4 of 13 eligible patients. Median time to progression was 14 months (based on either volume increase or hearing loss), and overall progression-free survival at twelve months was estimated at 64.7% (36).

Other agents such as mTOR inhibitors may halt tumour progression (231).

Medical therapies for this population must be tolerable, with care given to minimizing side effects. For young adults receiving bevacizumab or other agents which can affect future fertility, anticipatory care should include consultation with reproductive specialists.

98 Peripheral neuropathies that are unrelated to tumours can be treated symptomatically, with drugs such as gabapentin or pregabalin to control pain and other sensory symptoms (167).

Surgical management Until recently, surgery has been the mainstay of treatment for NF2 associated tumours, and continues to play an important role for most patients (186, 219). Surgical management should be carefully planned by surgeons experienced in the care of NF2 patients. The aim is to remove tumours before they cause irreversible damage, minimizing potential adverse surgical consequences, bearing in mind that operative morbidity increases with size of the tumour (167, 186). Tumour should be reserved for genetic testing, with patient consent (200).

Complete resection of schwannomas for NF2 patients is achievable at lower rates than for sporadic tumours (232), presumably because the schwannomas of NF2 tend to incorporate more nerve fascicles, with increased adherence to surrounding nerves (233). Risks associated with vestibular schwannoma resection include hearing loss and damage to the facial nerve. Some surgeons advocate for early surgery when vestibular schwannomas are <2cm in greatest diameter, to achieve hearing preservation with minimal surgical risks (186, 234). Other approaches include decompression of the internal auditory canal without tumour removal or partial tumour debulking to relieve symptoms of brain stem compression (186). A specific aim is to preserve the cochlear nerve, due to the potential future utility of a cochlear implant, which can provide stable serviceable hearing over at least 8 years in the majority of patients (235). Approaches to improving cosmesis, in the event of facial nerve damage, have been described, along with recommendations for assessing facial nerve outcomes during treatment (214).

Postoperative hearing preservation has been reported at rates of up to 50% over three years (234). In a group of 35 children with NF2 (47 vestibular schwannoma resections performed between 1992-2004), 55% of surgeries achieved hearing preservation at ≥70dB, with a similar hearing level to that reported in Friedman’s study (48%) (236). In another series of 29 paediatric patients (23/29 with NF2), hearing preservation was

99 possible in only 30% of cases, with greater risk of hearing loss and facial nerve damage (8%) following resection of larger tumours (232). Surgery is required in up to 30-60% of patients with spinal tumours with likelihood of surgery varying by tumour location (extramedullary tumours more likely) (181, 186).

Because surgery carries the risk of exacerbating neurologic deficits and other complications, evolving medical options are favoured where available.

Radiotherapy/Radiosurgery Stereotactic radiosurgery for vestibular schwannomas has been estimated to achieve tumour control in between 60-80% of the general NF2 population at 5 years (237), significantly better than the natural history of the disease. Hearing preservation in those with serviceable hearing was estimated at 73% after one year, 59% after 2 years and 48% after 5 years, with low risk of injury to the facial (5-12%) and trigeminal nerves (2-7%) (237, 238). Long-term results are less robust than for sporadic vestibular schwannomas (219). In one paediatric case series, whilst hearing preservation after gamma knife surgery compared favourably with adult patients (67% at 1 year, 53% at 5 years, n=11 tumours), tumour control was poor (35% at 3 years, n=17 tumours) (221). It should be noted that these studies have utilised alternative defined endpoints versus those recently recommended for studies of NF2 patients (22). Optimal comparability between natural history and treatment outcome datasets is dependent on measurement standardization.

There is concern regarding the increased risk of malignant transformation after radiosurgery in NF2 (188, 189). While NF2 patients number about 7% in studies of vestibular schwannomas treated with gamma knife surgery, nearly half of the cases of malignant change occur in the NF2 population, indicating that this treatment modality should be utilised with caution(189). Nevertheless, radiosurgery and radiotherapy may have a role in management of selected vestibular and other tumours, such as optic nerve sheath meningiomas (198, 238, 239).

100 Assistive Devices and Psychosocial Management Optimising quality of life through enhanced community participation can be achieved using a range of approaches including assistive devices to improve vision and communication (auditory brainstem implants, cochlear implants (232) and lip- reading). Allied health support to maximize ambulatory function and minimise risk of injury is important. Psychosocial support for affected individuals and families is critical.

Conclusion Neurofibromatosis type 2 is a rare autosomal dominant neurocutaneous disorder associated with multisystem effects, predominant in the central nervous system, related to loss of tumour suppressor function. Presentation in childhood is associated with more severe disease and risk of significant early morbidity and mortality. Whilst diagnosis in adults can be delayed due to a limited awareness of the condition among physicians, the challenge of timely diagnosis in children is further complicated by the variable presentation in this age group. Furthermore, the clinical diagnostic criteria used for adults may not be met during childhood. Careful skin and eye examination may uncover helpful clinical signs of NF2 in children. A high index of suspicion, genetic testing and attentive clinical follow up are needed to establish the diagnosis. When NF2 is confirmed, comprehensive multimodal surveillance is recommended at a minimum of annual intervals, and more frequently in cases where progressive disease and significant complications have been identified. The involvement of experienced specialist teams familiar with NF2 is recommended to optimise disease specific care and outcomes, and to facilitate inclusion of adults and children in natural history studies and treatment trials wherever possible.

101 CHAPTER 6: NF2 IN CHILDHOOD: EXPERIENCE AT THE CHILDREN’S

HOSPITAL AT WESTMEAD FROM 1994 TO 2015

Introduction Neurofibromatosis type 2 (NF2) presents in childhood in about 18 percent of cases(10). As a rare neurocutaneous syndrome (1:30,000), knowledge of the condition is limited in the community and among many medical practitioners. NF2 causes tumour formation within the nervous system causing dysfunction in motor and sensory systems, and the special senses involving hearing and vision. Cutaneous and ophthalmologic disease manifestations are important diagnostic features, and can cause symptoms in some cases(162, 164, 179). Progressive tumour growth may lead to complete loss of function including deafness, blindness, immobility and pain. Unfortunately, children with NF2 often experience more severe disease(10).

The presenting symptoms of NF2 in childhood frequently differ from the typical presentation with hearing loss attributable to vestibular schwannomas occurring in adulthood (10, 162, 221), which can lead to delayed diagnosis (179). A high threshold of suspicion for the diagnosis will assist with early recognition, patient education and appropriate ongoing monitoring for complications.

This chapter reports experience of NF2 in childhood at a single Australian centre, highlighting many of the challenges of diagnosis and management in the paediatric age group. The variable presentations and complications occurring in children are illustrated. Trends in treatment are outlined, reflecting the changing landscape for therapy to optimise outcomes in this potentially devastating condition.

Methods Records of children attending the Neurogenetics Clinic at The Children’s Hospital at Westmead meeting a clinical diagnosis of NF2 were reviewed over a 22-year period, from 1994 to 2015. Genotype was recorded where available, as well as whether the disease was inherited or sporadic. Clinical details were extracted including gender,

102 age at initial symptoms attributable to NF2, age at last follow up, evolving symptoms and signs, and criteria on which diagnosis was based. Complications experienced during childhood were recorded including visual and hearing impairment, weakness and gait abnormality, pain, and seizures. The impact of morbidity on community participation in each case is also described. Treatments provided are summarised including medical, surgical, radiotherapy interventions, hearing augmentation and allied health/rehabilitation strategies.

This project was reviewed and approved by the local Human Research Ethics Committee (LNR/13/SCHN/61).

Results Patients Fifteen children met a clinical diagnosis of NF2. Six were girls, and 9 were boys ranging in age from 5 to 18 years at first clinic visit (median= 9.1 years). Clinical characteristics of children at presentation are shown in Table 6.1. Five children were evaluated during a single consultation only. Otherwise, follow up ranged from 1.7 to 13 years (median 7.0 years). Three patients were first evaluated prior to the year 2000.

Patient 15 had inherited NF2, was seen only on one occasion aged 7 years, and was asymptomatic. Review of complications and treatment was therefore possible in 14 children.

Two children included in this series were followed into adulthood and treated with bevacizumab as described in Chapters 7 and 8 (Patients 3 and 6).

Genetics Genetic test results were available for nine children (60%). A single child had familial disease (paternal inheritance) and was asymptomatic at the time of evaluation, aged 7 years (Patient 15). Mosaic NF2 was diagnosed in one patient at 18 years of age, based on NF2 gene mutations present in 2 tumours, and absent from blood (Patient 6). Two

103 Table 6.1a Clinical characteristics of Australian children with NF2 at presentation Patient Age (y) 1st Presenting symptoms/ Diagnostic criteria for NF2 Age (y) at Genotype Inheritance (Gender) symptoms signs (age) diagnosis 1 (F) 5.5 Cutaneous/subcutaneous Hearing lossà 15 c.1564_1567 del Sporadic tumour BVS, CN V, VII schwannomas p.Glu522 Lysfs27 Longstanding CALM Spinal lesions (MRI 9y normal) 2 (M) 4 Focal seizures MRI (14y)àBVS, CN V 14 Sporadic schwannoma, Spinal tumours (not seen at 11y) 3 (F) 14 Hearing loss/tinnitus BVS ; MRI spine surveillance 15 Sporadic (20y)àspinal lesions 4 (M) 2.5 Cutaneous tumour ONSM (5y) 5 R198X exon 6 or Arg198 à Sporadic 5 Poor vision BVS, CN VII schwnnoma and stop (592 C->T) truncated protein Unilateral cataract, reduced spinal lesions (6y) VA 5 (M) 3 Head tilt Dermal lump-schwannoma 7 Sporadic CN IV palsy (6y) MRI->BVS, CNIV and V schw 6 (M) 16 Diplopia BVS, CN VI scwh 16 c.1336_1337del Sporadic CNVI palsy p.Arg446GlufsX48 (mosaic) frameshift mutation 7 (M) 8 Poor vision; CN IV palsy; BVS and CN IV schw; 8.5 c.559+1G>T Sporadic epiretinal membranes Spinal lesions (9y) 8 (M) 15 Double vision BVS, CN IV schw, 15 Sporadic CN IV palsy Spinal tumours

104 Table 6.1b Clinical characteristics of Australian children with NF2 at presentation Patient Age (y) first Presenting symptoms/ Diagnostic criteria for NF2 (age) Age (y) at Genotype Inheritance (Gender) symptoms Signs Diagnosis 9 (M) 5 Poor vision, proptosis, Bilateral ONSM (5y) 6 Sporadic reduced VA BVS (6y) CALM àsuspected NF1 Spinal tumours (7y) 10 (M) Infancy Dysmorphism Non-specific WM changes (6y) 12 4.7Mb deletion (NF2 Sporadic Developmental delay BVS, spinal tumours (12y) +34 other genes) Squint* 11 (F) 1.5 Poor vision SeizureàBVS, other CN schw (V) 14 Sporadic amblyopia, unilateral IC meningioma, spinal tumours retinal hamartoma 12 (M) 4 Unilateral hand Unilateral ONSM, BVS, CN V schw 5 c.773G>A, p.Trp 258 X Sporadic weakness Spinal and brachial plexus tumours (alternate splicing at exon 8 ) 5 Poor vision 13 (F) 10 Headaches BVS 12 1.98Mb deletion Sporadic Other IC schw (CN V) (NF2 +3 other genes) 14 (F) 4.5 Poor vision BVS 4.5 c.169C>T, p.Arg57Ter Sporadic Diplopia Other IC schw (CN III, VII) Hz truncating NF2 plaques IC meningioma mutation exon 2 Depigmented macules Spinal tumours 15 (F) Nil at 7y Asymptomatic Family History 3 Familial variant Paternal Genetic testing c.1165C>T p.Gln 389 BVS-bilateral vestibular schwannomas; CALM-café au lait macules; CN-cranial nerve, F-female, Hz-heterozygous, IC-intracranial, M-male, ONSM-optic nerve sheath meningioma, schw-schwannoma, VA-visual acuity, WM-white matter, y-years.

105 children had whole gene deletions as part of a larger chromosomal deletion. In Patient 13, a 1.98Mb deletion in chromosome 22 was identified, encompassing the NF2 gene, and all aspects of the clinical presentation were consistent with NF2. Patient 10 (4.7Mb deletion) was identified prior to becoming symptomatic with NF2, due to other medical problems presenting in infancy including dysmorphism, and developmental delay. Diagnosis of NF2 was based on CGH microarray result followed by MRI demonstrating bilateral vestibular schwannomas and spinal tumours at age 12 years. Frameshift mutations causing a truncated protein product were typically seen in the other five patients.

Presentation and Diagnosis Presenting symptoms and signs are summarised in Table 6.2. 57% of children (N=8) experienced difficulties with vision early on. Visual acuity was reduced in four children (28%), attributable to optic nerve sheath meningioma in three cases (21%) and retinal hamartoma in one case at age 1.5 years (Patient 11). Five children (36%) had eye movement disorders secondary to cranial nerve palsies. Head tilt with cranial nerve IV palsy was observed in early childhood in one case (Patient 5), and occurred in middle childhood in the developmentally delayed child (Patient 10). Other presenting symptoms included hand weakness, headache, and seizure, each affecting one child. Two patients had cutaneous/subcutaneous lumps assessed at the first medical visit. Hearing impairment as first manifestation of NF2 occurred in only one patient, aged 16 years.

Mean age of occurrence of first NF2-associated symptoms was 6.1 years (range 1.5- 16 years). For sporadic patients, diagnosis occurred at a mean age of 10.6 years (range 4.5-16 years). Diagnosis was delayed up to 12.5 years following first presentation (Patient 11), with a mean delay of 3.6 years.

106 Table 6.2. Presenting symptoms of NF2 among Australian children compared with other published populations*

Age Group Hearing Tinnitus Vertigo/ Muscle Facial Seizures Pain Headache Visual Sensory Footdrop Cutaneous Other Ref loss loss of weakness nerve involvement symptoms balance wasting palsy

a ≤ 18yrs 1 1 - 1 - 1 - 1 8 - - 2 2 This study N=14 (7%) (7%) (7%) (7%) (7%) (57%) (14%) (14%) (head tilt; dysmorphism/ DD) 10 yrs 2 - - - 3 3 - 1 1 - 1 NI - (165) (18%) (27%) (27%) (9%) (9%) (9%) N=11

<16yrs 1 - - 2 - 1 2 - 8 b 5 c - (162, 206) N=18 (5%) (9%) (5%) (9%) (44%) (28%)

≤10 yrs 4 1 - 3 d 5 e 8 - 2 4 f 1 1 1 1 (10) N=30 (13.5%) (3%) (10%) (17%) (27%) (6%) (13.5%) (3%) (3%) (3%) (3%) Weight loss (glioma)

g ≤17yrs 3 1 - 2 2 - - - 1 - - NI 3 (164) (25%) (8.3%) (16.5%) (16.5%) (8.3%) (25%) N=12

h i ≤ 15yrs 1 2 - 6 1 1 1 - 7 - - 8 CALM 3 (179) N=24 (4%) (8%) (25%) (4%) (4%) (4%) (29%) (33%) (12.5%) 3 tumours (12.5%)

<17yrs 5 - - - - See other See - 3 - See other 5 a (+1 CALM) 5 j+ 6k (221) N=25 (20%) other (12%) (24%) (20% + 24%)

*Data reproduced from Chapter 5 with addition of Australian patients. a Painful or growing skin tumours; b cataracts (N=3), oculomotor nerve (N=2), diplopia, epiretinal hamartoma, epiretinal membrane (N=1); c oculomotor nerve and skin (N=1); d spinal schwannomas (N=2), neuropathy (N=1); e presumed secondary to vestibular schwannoma; f plus nystagmus due to retinal hamartoma (N=1); g swallowing difficulty, foot eversion, nystagmus; h strabismus (N=3), amblyopia and strabismus (N=2), cataract (N=1), amblyopia (N=1), pigmentary retinal hyperplasia (N=1); i ptosis (N=2); voice changes/hiccups (N=1); j gait disturbance, leg or neck pain, footdrop due to peripheral nerve sheath or intradural-extramedullary tumour; k seizure, abdominal pain, incidental finding on chest x-ray, hoarseness (N=2); DD-developmental delay; NI-not included -skin lumps and cataracts excluded in (165) as usually asymptomatic; skin lumps and amblyopia (non-specific) not included (164); CALM-café au lait macules.

107 A lack of diagnostic clarity was evident in three children for whom other neurocutaneous disorders were initially considered. Patient 1 had atypical café au lait macules (less than six lesions), and a subcutaneous tumour (pathology consistent with neurofibroma). This child was followed with surveillance for complications of NF1, but recognized as being atypical and not fulfilling clinical diagnostic criteria for NF1. Mosaic NF1 was considered. Occurrence of hearing loss in adolescence with appearance of bilateral VS on neuroimaging clarified the diagnosis. At age 5 years, NF1 was also the initial working diagnosis for Patient 9 who had café au lait macules, hypopigmented macules and reduced visual acuity. The diagnosis of NF2 became evident when an optic nerve sheath meningioma rather than optic nerve glioma was demonstrated on cranial MRI. Patient 2 first presented to another service with seizures and periventricular lesions, interpreted as subependymal nodules, leading to a clinical diagnosis of tuberous sclerosis (TSC). The diagnosis was revised at age 14 years, when bilateral VS were seen on MRI along with a cervical intramedullary tumour with large syrinx. Seizures in this patient were likely secondary to cortical dysplasia.

During follow up of this cohort, bilateral vestibular schwannomas were evident on cranial MRI in all patients, constituting important supportive diagnostic criteria in most cases. Multiple other intracranial and intraspinal tumours were also seen in the majority of children at diagnosis, and occasionally during follow up.

Complications Major clinical problems occurring during childhood are shown in Table 6.3 along with characteristics of hearing and vision, and impact on community participation in symptomatic individuals. Table 6.4 summarises the incidence of specific disease complications during childhood in this cohort; information is available to late adolescence for 12 of 14 patients, with the remaining two patients aged 6 years.

Eight of 14 children experienced some hearing loss, with unilateral deafness in 2 cases. Visual deficits continued to be the most common complication, affecting 10 children (71%), with significant reduction in visual acuity in six cases (43%) and ocular motility problems in four cases (28%). Severe visual impairment (reduced visual acuity) was attributable to optic nerve sheath meningiomas (N=3) and retinal

108 Table 6.3a Characteristics of children with NF2 at last follow up, including complications, hearing and vision, and impact on community participation* Patient Follow Age Major clinical problems Hearing** Eye findings Visual Acuity Other features Community Participation up (y) (y) (age, y) (age, y) 1 8 17 Hearing loss with tinnitus Moderately Unilateral ERM Normal Minor limitation (15) severe loss / and retinal Communication Discomfort from Normal hamartoma subcutaneous nodules contralateral 2 5 16 Seizures (4) Normal Bilateral cataracts 6/120 6/12 Cervical Seizure precautions Unilateral visual impairment Retinal ependymoma Minor limitation mobility (13) hamartoma with syrinx Driving with glasses Neck, back, shoulder pain Visual field defect (13) 3 1 visit 16 Unilateral hearing loss Moderately Bilateral ERM Normal Minor limitation severe loss / Unilateral retinal Communication Mild hamartoma contralateral 4 13 18 Visual loss (6m) Normal Unilateral NLP 3/60 Bilateral ONSM Driving restriction Gait abnormality (9) blindness with (with glasses) Moderate limitation Scoliosis (13) proptosis (5y) Vision Short stature Minor Mobility Hoarse voice (15) 5 11 18 Head tilt/diplopia Unilateral NA NA CN IV palsy Limitation Seizures moderate Communication Hand weakness (8) loss Major mobility Back pain, foot drop (12) Fine motor Unilat hearing loss (13) Normal Calcified Leg weakness and contralater meningioma Seizure precautions urinary dysfunction (14) al cavernous Home schooling Visual loss (15) sinus Voice change (15) DECEASED age 18 years 6 1 visit 18 Tinnitus (16) Normal Unilateral Normal No limitation cataract

109 Table 6.3b Characteristics of children with NF2 at last follow up, including complications, hearing and vision, and impact on community participation* Patient Follow Age Major clinical problems Hearing** Eye findings Visual Acuity Other features Community up (y) (y) (age, y) (age, y) Participation 7 7 16 Mild visual loss Normal Bilat cataracts 6/9 6/20 Cholesteatoma Minor limitation ERM Vision Unilat retinal Anxiety / school Major limitation hamartoma refusal School attendance 8 1 visit 18 Diplopia (15) Profound Papilloedema 6/9 6/60 Additional tumours: Significant limitation Visual loss (17) loss Visual field CNV schw Communication Vertigo (16) (18y) / defect Hand schw Moderate Hearing loss (17) Moderate RAPD limitation mobility Hand cramps (15) contralat Multiple IC Leg weakness loss meningiomas Driving restriction Gait abnormality (15) Multilevel spinal Back pain (15) disease Urinary dysfunction (16) 9 13 18 Unilateral blindness (5) Profound Bilateral NLP 6/36 Bilateral ONSM Reduced dancing as Reduced vision in other loss cataracts Spinal tumours young adult eye (13) (11y) Bilateral ERM (cspine; asym- Dizzyness (10) Moderate ptomatic cord Other minor Hearing loss (10) contralat compression; limitations Periorbital oedema (14) loss (14) multilevel other Unsteady gait (16) disease) 10 5 16 Bilateral spasticity Moderate 6/12 6/12 Spinal Limitation due to non- Developmental delay unilat loss tumours- NF2 phenotype in early Scoliosis (14) thoracic schw childhood, NF2 from Head tilt (11) 11y Hearing loss (11) Mild (special school, Paresthesias hands (11) Contralat reduced mobility and Back and hip pain (11) loss hearing, Leg weakness (11) pain)

110 Table 6.3c Characteristics of children with NF2 at last follow up, including complications, hearing and vision, and impact on community participation* Patient Follow Age Major clinical problems Hearing** Eye findings Visual Acuity Other features Community Participation up (y) (y) (age, y) (age, y) 10 ctd 5 16 Unsteady gait (12) See above See above See above See above See above Mild visual impairment (14) 11 3.5 17 Visual impairment (1.5) Moderately Unilateral 6/5 6/60+1 Narcolepsy Minor limitation Hearing loss (13) severe loss retinal Vision Seizures (14) Normal hamartoma Cervical schw Mild facial weakness contralater (macula) causing cord Seizure CNVII palsy (post-op) al compression Precautions 12 1 visit 6 Hand weakness (4) Normal NA NA ONSM Minor limitation Visual impairment (5) Vision Fine motor (Piano) 13 3 16 Hearing loss Moderate Nil Normal Minor limitation loss Communication Normal contralat 14 1.7 6 Visual impairment Normal CNIII: diplopia Minor limitation and ptosis Vision àamblyopia 15 1 visit 7 Asymptomatic Normal Bilateral Normal No limitation cataracts

* Major complications included only. Incidence in Table 6.4 represents a comprehensive number of complications. ** Hearing loss according to Goodman as follows: mild 25-40 decibels (dB), moderate 45-55dB, moderately severe 60-70dB, severe 75-90 dB and profound >90dB (240). CN-cranial nerve, contralat-contralateral, ctd-continued; ERM-epiretinal membranes, IC-intracranial, NA-not available, NLP-no light perception, ONSM-optic nerve sheath meningioma, RAPD-relative afferent pupillary defect, unilat-unilateral.

111 Table 6.4 Incidence of NF2 disease complications during childhood (≤ 18yrs, N=14) Complications/Disease Manifestations Number of patients Percentage

Hearing loss 8 (12 ears) 57 (43)** Unilateral deafness 2 14 Visual difficulties 10 71 Reduced visual acuity 6 43 Blind in one eye 3 21 Eye movement disorder 4 28 Facial nerve palsy (post-operative VS resection) 2 14 Hoarse voice 2 14 Pain 10 71 Back/neck pain 4 28 Headaches 9 64 Regular analgaesics 3 21 Other sensory symptoms 6 43 Weakness/Muscle wasting upper limbs 2 14 Weakness/wasting lower limbs 3 21 Gait abnormality* 7 50 Urinary dysfunction 2 14 Seizures 3 21 Psychological distress (anxiety/depression) 4 28 Anxiolytic/antidepressant 2 14 Cutaneous/subcutaneous tumours 3 21 Other cutaneous features 13 92 CALM 7 50 Hypopigmented macules 7 50 NF2 plaques 7 50 Ophthalmologic features 8 57 Cataracts 5 (9 eyes) 36 (32)** Epiretinal membranes 3 (5 eyes) 21 (18)** Retinal hamartomas 5 (5 eyes) 36 (18)**

*Gait abnormality due to weakness, pain or unsteadiness; ** Percentage of ears or eyes affected in entire cohort (N=28).

112 hamartoma (with macular involvement, N=1). Retinal hamartoma caused unilateral reduced visual acuity in one other child (6/120, Patient 2). Visual field defect was recorded along with reduced acuity in this case along with the last child (acuity 6/60, Patient 8) who had increased intracranial pressure associated with multiple intracranial tumours. Although ophthalmologic features of cataracts, epiretinal membranes and retinal hamartomas affected approximately one quarter to one third of children, most were not symptomatic. Similarly, cutaneous features occurred as an important diagnostic clue, but only occasionally caused clinical difficulties, usually due to discomfort/pain in tumours.

Clinically significant weakness was less common. Two young children had functionally limiting arm/hand weakness at the ages of 4 and 8 years (Patient 5 and 12; 14%). Weakness in the lower extremities affected 3 patients (21%). By the time children with NF2 were ready to transition to adult services, 10 of 12 patients experienced pain, with three requiring regular analgaesia. Seven of these twelve older adolescents experienced gait difficulties. All remained independently mobile, except for Patient 5 who had significant multilevel spinal disease causing pain, weakness and urinary dysfunction, and required a walker and wheelchair. Depressed mood and/or anxiety occurred in four of 14 patients (28%), treated with medication in two cases. Approximately 20% of the population experienced seizures (3/14).

In terms of the impact of disease manifestations on community participation (Table 6.3), only one patient (with mosaic NF2) experienced no limitations approaching adulthood. Two children were unable to attend school, in one case due to multiple disabilities, and in the other case due to mild visual impairment associated with significant psychological distress. Two adolescents were unable to drive due to visual impairment in one case, and coincident visual impairment and weakness in the other.

Treatment Therapy provided for symptomatic patients is shown in Table 6.5. Only a single young patient (aged 6 years) received no active treatment. Medical therapy was provided for 9 patients, surgery for 11 patients, and radiotherapy for 2 patients. In those requiring medical management, steroids, analgesics, anticonvulsants, and

113

Table 6.5a Active management of disease complications for Australian children with NF2 Patient Age Medical Management* Surgical Management* Complications of Other (y) (indication/comment) [total number of procedures] management 1 17 Cutaneous schwannoma (1) Nil Hearing aid

2 16 Anticonvulsant Intramedullary spinal tumour (tanycytic ependymoma) / drainage Post-operative pain Analgesic of synrinx (1) à improved over months Trace leg weakness

3 16 Steroid Unilateral VS (1) Nil Hearing aid (acute hearing loss) 4 18 R ONSM Short stature Orbital radiation R orbital decompression post radiation Glasses/telescop Lumbosacral laminectomy L4/L5 schwannomas (3) e/braille 5 18 Quinidine CN IV Nil significant Mobility aids Hydroxyurea L posterior interosseous nerve (elbow) for hand function (Walker/ (IC tumours, prior 2005) Cutaneous schwannomas wheelchair) Tongue plexiform neurofibroma Splints Tendon transfer (finger extensors) x2 Cervical laminectomy C1/2, then C7/8 Schwannoma resection (8)

6 18 Intracranial meningioma adjacent Complete CN VI palsy CN VI (1)

7 16 Anxiolytic/antidepressant Cholesteatoma (1) Nil significant Psychologist

8 18 Antidepressant Cutaneous mass (forehead) Mobility aids Other cutaneous tumour (5) Thoracic laminectomy (meningioma) Psychologist Unilateral VS CN VII palsy (4)

114

Table 6.5b Active management of disease complications for Australian children with NF2 Patient Age Medical Management* Surgical Management* Complications of Other (y) (indication/comment) [total number of procedures] management 9 18 Steroid Orbital decompression (ONSM) Nil Hearing aid Somatostain analogue Unilateral VS Radiotherapy (meningiomas) (2) VEGF inhibitor (VS growth/hearing loss; ONSM) 10 16 Analgaesic Cleft palate repair-not NF2 related Hearing aid VEGF inhibitor (2) Proteinuria (VS growth/hearing loss; Hypertension Psychologist pain) Antihypertensive 11 17 Steroid Retinal hamartoma Nil Psychologist Anticonvulsant C6 schw with complications Meningocoele with Analgaesic (headache) Repair meningocoele elevated ICP and (3) mild CN VII palsy 12 6 Nil Nil NA Nil 13 16 VEGF inhibitor Nil Proteinuria (VS growth/hearing loss) 14 6 Nil Resection meningioma/schwannoma Unilateral ptosis Eye patching (one tumour adjacent CN III) (2)

C-cervical CN=cranial nerve, IC=intracranial, ICP=intracranial pressure, L=left, NA=not applicable ONSM=optic nerve sheath meningioma, R=right, schw=schwannoma, VEGF=vascular endothelial derived growth factor, VS=vestibular schwannoma.

115 anxiolytic/antidepressant agents were prescribed. Oncologic treatment to control tumour growth was provided in four cases. Quinidine and hydroxyurea were trialled in one patient with severe disease prior to 2005, with limited success. This patient died aged 18 years. One child received somatostatin analogue (for optic nerve sheath meningioma) for approximately 12 months, without definite benefit. Subsequent to 2009, three patients were treated with bevacizumab (vascular endothelial growth factor inhibitor) during adolescence, over a total of approximately eight patient years follow up, with stabilization of symptoms and tumour growth (see Chapter 8). Side effects of bevacizumab included proteinuria in two patients and hypertension in one patient, which were managed with dose adjustment and anti-hypertensives.

Surgery for non-NF2 associated indications occurred in two patients-cleft palate repair in the child with large chromosomal deletion and cholesteatoma in the other case. Ten patients (71%) underwent 26 surgical procedures for NF2 associated indications, with a mean of 2.6 procedures per patient (range 1-8). Three patients had unilateral vestibular schwannoma resection. Other procedures involved the eye (1), orbit (2), other intracranial tumour resection (4), spinal surgery (7), resection of peripheral schwannoma (1), and resection of cutaneous/subcutaneous lumps (3). Five procedures (19%) were associated with surgical complications. None were severe or life threatening. Facial nerve weakness occurred following vestibular schwannoma resection in one case. Transient facial nerve palsy complicated resection of cervical schwannoma in another case, with raised intracranial pressure and meningocoele. Worsening of pre-existing cranial nerve palsies occurred post-surgery in two cases (14%; cranial nerves III and VI). Post-operative pain and lower extremity weakness complicated laminectomy for cervical ependymoma resection and drainage of syrinx, which improved over time.

Radiotherapy was provided for two patients (14%), both indicated for optic nerve sheath meningioma, with improvement. During three and 10 year follow up post- treatment (Patients 9 and 4 respectively), the only side effect of radiotherapy observed was short stature for the child treated at a younger age of 8 years. Additional supportive therapy was provided for eight patients (57%), including hearing augmentation and psychology input in four cases each (28%).

116 Discussion Features of NF2 at Presentation and Diagnosis in Childhood This cohort of children illustrates many of the features of NF2 presenting to paediatric clinics. The diversity of initial symptoms is most striking in this population along with other paediatric cohorts (Table 6.2). Although visual changes were most common, the prevalence at presentation in this study was higher at 57%, compared with other reports (8.3-44%)(162, 164, 206). Cutaneous features followed as the next most common abnormality seen in early life. However, neither ophthalmologic abnormalities nor cutaneous abnormalities alone constitute a clinical diagnosis of NF2. Rather, an astute clinician will ensure signs in the eyes and on the skin are carefully looked for in any child with features that may arise in NF2, including focal neurologic signs. Clinical follow up, with surveillance for new symptoms and signs, should be established(241).

The mean age at clinical diagnosis of NF2 for sporadic patients in this study was 10.6 years, compared with 8.8-12.9 years in four other recent paediatric series(164, 179, 221, 242). Delay of 3.6 years between first symptoms and diagnosis in this group compares favourably with another study reporting 8.5 years(164).

Hearing loss and tinnitus occurred at a low prevalence in only one child (7%) at presentation, within the range observed in the other six populations of children tabulated for comparison (4-25%). Considering numbers presenting in all seven populations, a prevalence of 12.7% was evident for hearing loss as a presenting symptom of NF2 in childhood (17/134; Table 6.2). The same patient with hearing loss in this study also experienced tinnitus. It is possible that other symptoms such as tinnitus and dizziness may have occurred in the absence of hearing loss in a few additional children in other studies, so that 12.7% may be an underestimate of symptoms of vestibular schwannoma at first presentation. Even so, first presentation of NF2 with symptoms due to vestibular schwannomas in childhood likely falls within the lower range of the 15-30% reported previously(4).

This series also demonstrates the potential diagnostic confusion among neurocutaneous syndromes (including NF1, NF2 and TSC) in early life, before

117 additional manifestations become obvious. Overlaps occur in cutaneous and subcutaneous features including tumours, visual impairment and other focal neurologic deficits, along with seizures. Historically, there has been confusion in the diagnosis of NF2 and the more common disorder of NF1 (2, 162, 179). There are also overlaps in the clinical signs between NF2 and TSC(243) . Nevertheless, a constellation of diagnostic signs exists for each condition, which are recognisable to the experienced clinician. The establishment of clear clinical diagnostic criteria along with genetic testing has improved accurate diagnosis over the last couple of decades. All the same, surveillance over time may be required for diagnostic certainty in children, particularly if genetic testing is not available, or if testing is negative for the condition suspected. Recommendations for monitoring are available to assist practitioners in cases of possible NF2, along with early identification of complications in children with established sporadic and inherited disease (241).

Genetics It was surprising that only one patient (7%) in this study had familial NF2, in contrast with other reports of between 20-66% of affected children having inherited NF2 gene mutations (179). Although advances in prenatal screening now allow for parents to reduce risk of transmission of genetic disorders to their offspring, a higher proportion of inherited cases were expected in this study dating back to 1994. A majority of patients had nonsense or frameshift mutations in the NF2 gene causing a truncated protein product, as expected, in children with severe disease. In contrast, two patients were found to have larger deletions involving the entire NF2 gene, along with a number of other genes. The course of disease in such individuals is expected to vary with the extent and location of the deletion. Certainly, other children with large chromosomal deletions have been reported having features shared with Patient 10, including NF2 as well as abnormal craniofacial development with cleft palate, reflecting contributions of the deleted NF2 gene along with adjacent genes(244).

Complications A range of complications was evident among children included in this study. Visual problems remained important, affecting nearly three quarters of patients. In cases of significant functional impairment in vision and hearing, patients often maintained

118 independence due to reliance on the contralateral eye or ear. Severe disease manifestations were seen in patients with bilateral loss of function and spinal disease. Most experienced some limitations during childhood, with significant NF2-associated disability in four children, as well as the patient with the larger chromosomal deletion. One child with severe disease did not survive into adulthood (6.7% mortality). This compares with three of 23 children (11.5%) in another study, who died at ages 2, 20 and 24 years (162). Given the complexity of disease manifestations in NF2, transition to adult services requires careful planning and information transfer between treating specialists. Ideally members of the treating team will continue care from childhood into adulthood.

Psychological distress requiring therapy occurred in more than a quarter of patients, underlining the importance of psychosocial support in this population as recognized in other NF centres(245, 246). Wherever possible, the treating team should include members such as nurses, genetic counsellors and psychologists, experienced in the care of children and families with NF2. With the prospect of cumulative functional impairment over time, the usual transition to independence from parents is compromised in NF2, impacting on both the affected individual and close family members. Financial and quality of life costs should be considered in cost- effectiveness analyses of novel treatments in future.

Assignment of level of disability in this study was based on the morbidity described and clinical knowledge of the patients. Eighty six percent of patients (13/15), experienced some limitations during childhood. The two unaffected children included one with inherited NF2 at a young age (7 years), and the patient with mosaic NF2 at 18 years of age. This is similar to 83% of children (10/12) affected in at least one of four domains (vision, hearing, ambulation and grade level), in a US study (164). This study could have been improved by utilization of a validated scale to allow comparison of level of disability and quality of life with other populations, and as a natural history baseline for interpretation of functional change in children managed with different treatment protocols in future. Very little other comparative data is currently available for children with NF2, however tools such as the NFTI-QOL(247) or SF36 could be candidates. SF36 results for a group of eight children aged 10-17 years, from USA, have recently been published, which interestingly, did not show

119 obvious deficits in quality of life compared with population norms for young adults aged 18-24 years (norms not available for children)(246).

Treatment A diverse range of treatment was provided for these children, underlining the need for multidisciplinary communication and cooperation in the care of NF2 patients. Individual treatment decisions often proceeded only following consensus among the team of treating specialists. Multimodal therapy was required in the majority of symptomatic patients (10/14; 71%). Surgical treatment was offered to more patients than medical management in this series (11/14 patients totalling 26 procedures, versus 9/14 medical). This is similar to other reports including 12 children at a US centre prior to 2003, treated with 22 procedures in 10/12 patients (dermal, spinal or cranial, and all required at least one spinal or cranial procedure)(164). Fewer procedures were performed in an Italian series of 24 children (22 procedures, predominantly cranial)(179).

Three of our patients received VEGF inhibitor treatment for vestibular schwannomas. The response was modest in Patient 9 compared with Australian adults (see Chapter 8), and associated with a clinical impression of stable disease in the other two patients. Proteinuria affected two patients and hypertension one patient, requiring only modest changes in treatment. Results have been published for only a small number of children treated with bevacizumab to date, with definite slowing of VS growth in seven patients from France(248). Detailed assessment of efficacy is important in larger groups of children, given observation of reduced response in children compared with adults in another study (249). It remains to be seen, what is the optimal time for commencing therapy, and whether impact on renal function or other side effects will limit long-term treatment with VEGF inhibitors. Although hospital admissions were not overly prolonged (data not shown), admissions along with regular disease surveillance represent a significant burden of time, particularly for the patient requiring eight procedures during childhood. Surgical complications occurred in approximately 25% of patients, without a comparable number reported in the literature from other sites. These included recognised complications for the procedures performed, and no life threatening adverse effects.

120 Radiotherapy was not commonly provided, and beneficial in both children with large optic nerve sheath meningiomas treated in this series. This modality halted progression of optic nerve sheath meningioma for at least 8 years in another child(164). Auditory rehabilitation with hearing aids has been offered to selected children as accepted standard of care. None of our patients have been considered for auditory brainstem implantation or cochlear implantation, approaches that warrant future consideration (250-252). Lastly, various additional allied health interventions provided supportive care, which played an important role in many cases.

Conclusion In conclusions, children with NF2 present with a variety of symptoms and signs. The diagnosis may take time to establish with certainty, using clinically based criteria, neuroimaging and genetic testing. Cutaneous examination and ophthalmologic/visual assessment deserve special attention in childhood as a source of diagnostic clues and possible morbidity. The complications of disease are equally diverse, and typically require a multidisciplinary/multimodal approach. There is cumulative multisystem functional decline in many children with NF2, without current options for cure. Timely diagnosis, identification of complications, and consultation with specialists in NF2 management, are more important than ever, as refinements in treatment evolve with a view to minimizing disability and risk of mortality in all affected individuals.

121 CHAPTER 7. NF2 PATIENTS TREATED WITH BEVACIZUMAB: EPIDEMIOLOGY, FUNCTIONAL STATUS AND QUALITY OF LIFE

Introduction As a tumour suppressor syndrome, NF2 manifests predominantly with formation of multiple benign tumours in the central and peripheral nervous systems and the skin. Since establishing the genetic basis of disease with identification of the NF2 gene in 1993(14, 17), the clinical characteristics of NF2 have been well characterized in the literature (40, 167, 175, 241), although awareness of the condition among health professionals is generally limited due to rarity of the condition. Significant advances have been made regarding the molecular basis of disease and pathophysiology(253), paving the way for novel therapeutic approaches. Accelerated translation of this knowledge into the clinical trials setting has been the focus of international research collaborations (23), with the vascular endothelial growth factor bevacizumab one of the first agents showing promise in initial case reports and small series of patients. In considering response to therapy, appropriate objective disease specific end points have been proposed and assessed in early trials. However, these end points do not necessarily represent overall functioning, disability secondary to the condition, or patient reported quality of life.

In preparation for treatment of the first Australian patients with NF2 using bevacizumab, assessment of functional status and quality of life at baseline was considered an important complement to established outcomes of hearing function and radiologic response.

This chapter outlines the rationale for selection of patients for bevacizumab therapy, and describes baseline characteristics in detail including presentation, complications of disease, and treatment to date. Functional impact of disease and quality of life are reported, in comparison with published data from other populations. These data form the baseline against which to measure changes associated with bevacizumab treatment.

122 Methods Patient population Referrals were received from specialists seeing NF2 patients around Australia and in New Zealand. All patients met clinical criteria for diagnosis of NF2 (166), and had been seen by a clinical geneticist. Clinical review was undertaken by a neurologist and oncologist, either at Westmead Cancer Care Clinic (adult patients; SAH/MW), or The Children’s Hospital at Westmead (paediatric patients; SAH/GMcC). An assessment of disease and management recommendations were made for all patients.

Suitability for trial of bevacizumab therapy was considered based on indications in published literature at that time, predominantly loss of hearing in the only hearing ear, according to the promising data of Plotkin et al (37). Detailed historical data, review of symptoms, examination findings, QOL assessments, and review of neuroimaging were undertaken to characterize baseline clinical status, disease burden and quality of life for the subset of patients enrolled on the prospective trial of bevacizumab therapy.

Disease Characteristics Presenting symptoms, age at presentation and age at diagnosis were recorded for treated patients, along with inheritance pattern (sporadic versus familial disease), and genotype where available. Active medical problems were summarized. An overview of tumour burden was based on number and location of tumours. A detailed analysis of radiologic disease burden is beyond the scope of this chapter. Greater detail is included in Chapter 8 which considers volumetric response of target and selected non-target tumours in treated patients, and in Chapter 9 which presents an assessment of tumour response across multiple tumours in a single patient.

Hearing assessment included pure tone audiometry and speech discrimination score (SDS, also known as word recognition score, WRS). SDS was used as the primary hearing outcome consistent with proposed functional outcomes for treatment of VS in NF2(22). Hearing loss was also described using the American Academy of Otolaryngologists-Head Neck Surgery grading system for comparison with other populations (254). Presence of other clinical features such as ocular complications, (subcapsular cataracts, retinal hamartomas, epiretinal membranes) and visual

123 impairment, epilepsy and peripheral neuropathy were recorded. Prior treatment received was documented including medical and surgical management.

Functional Status and Quality of Life Psychosocial factors were recorded during clinical evaluation including impact on schooling or employment, and independence such as ability to drive.

Functional status and quality of life were assessed using three self-administered patient reported measures: a novel NF2 symptoms questionnaire, developed for this study, with linear measure of overall wellbeing (NF2 linear overall wellbeing scale, LOWS, see below), the Speech, Spatial and Qualities of Hearing Scale (SSQ49)(255), and the Australian Short Form 36 (SF36) quality of life questionnaire.

The NF2 symptoms questionnaire devised for this study, consisted of 20 items concerning symptoms and functional parameters routinely evaluated during a comprehensive systems review for complex NF2 patients (targeted to neurologic and oncologic symptoms; Appendix 6). Items in this questionnaire are listed in the NF1 symptoms questionnaire, with the addition of tinnitus. Frequency of clinical symptoms was scored on a 6-point scale where 0=nil, 1=less than monthly, 2=monthly, 3=weekly, 4=daily, 5=many times a day. A total score was calculated for each patient, with a higher score representing greater symptom frequency/functional impact. One additional open question was included.

The estimate of overall wellbeing was derived using a linear scale ranked from low to high (Linear Overall Wellbeing Scale-LOWS, Appendix 6), where the overall wellbeing score was calculated as a proportion of the total length of the line (distance along the line/14.5).

The SSQ is a freely available 49 item self-reported questionnaire of auditory disability (validated for individuals older than 18 years), which includes questions assessing complex listening skills in real-life situations (Appendix 7)(255, 256). It was designed as a self-reported assessment tool for use in interventional studies. The 49 items are clustered in 3 domains, assessing speech (14 items), spatial features (17 items) and

124 qualities of hearing (18 items). A summary score was calculated for each domain, along with mean scores for the group of patients.

The SSQ has not previously been used with NF2 patients to our knowledge. However, this tool has been used in evaluation of patients undergoing surgical removal of unilateral vestibular schwannoma (257), in treatment trials assessing utility of hearing aids(258) and cochlear implantation (257, 259). In these interventional studies, the SSQ has effectively established either no difference (260) or a statistically significant difference between interventions (cochlear implantation; post intervention SSQ results not shown here)(259). An equivalent standardized tool was not available for evaluation of children at the time of this study.

SSQ responses from three separate hearing impaired non-NF2 populations were sourced as a comparison with results for our NF2 patients. Population 1 represents the original cohort of Gatehouse and Noble involving 153 older adults, presenting to a general audiology service (males 73, females 80; average age 71y, SD 8.1)(255). Causes of hearing loss were not detailed, but likely include presbycusis in most cases. Hearing impairments were reported as 38.8dB (SD 15.5) (calculated as PTA using decibel levels at 0.5, 1, 2, and 4kHz) in the better ear and 52.7dB (SD 24.4), in the worse ear(255).

Population 2 consists of a younger patient group (N=58) with unilateral deafness of various aetiologies assessed for effectiveness of bone-anchored hearing aids (BAHA) (average age 56 years, range 30-76y; 19 males, 39 females) (260). Sporadic vestibular schwannomas affected 45% (27/58 patients; NF2 associated tumours not included; in the remainder childhood illness or congenital deafness N=7, sudden onset hearing loss in adulthood N=9, and acquired deafness following surgery or in association with systemic illness N=15). 40% of patients had hearing impairment in the contralateral ear (24/58; >20dB). Percentage change in speech discrimination scores were reported without baseline PTA.

Population 3 summarises responses from twenty adults with unilateral sensorineural deafness of variable aetiologies (not including NF2), treated with cochlear implantation (259). Mean duration of deafness was 8.9 years (SD 11.6), with surgery

125 at mean age 51.6 years (SD 12.5). Mean pure tone averages (0.5, 1, 2 and 4 kHz) were reported for individuals with some hearing loss in the contralateral ear 60.1 dB (SD: 14.4 dB) and 17.7 dB (SD: 9.1 dB) for those with contralateral normal hearing. Pre-treatment results are shown.

Quality of life was measured using the Medical Outcomes Study 36-Item Short Form (SF36) questionnaire (Appendix 4) (144, 145), which has become one of the most widely used general health status questionnaires (146). This tool had been used in pre- and post-treatment studies of individuals with sporadic VS (261, 262), and since design of this protocol, also in NF2 patients (263). The SF36 requires patients to choose one of several responses to 36 questions across eight health domains: physical functioning, social functioning, role of limitations due to physical and emotional problems, vitality, general and mental health, and bodily pain(145). Questionnaires were scored using the method of Ware et al(145). Baseline responses were compared with norms for the healthy Australian population available from the Australian Bureau of Statistics (147), and responses for other populations with sporadic vestibular schwannomas and NF2 (187, 261, 263).

This project was completed with approval from the Children’s Hospital Westmead Human Research Ethics Committee (10CHW14).

Results Patient population: Adults Nineteen adults were referred for evaluation between 2009-2011, ranging in age from 17 to 57 years (mean 34.7 years, SD 12.8 years; 10 females, 9 males). Selected patients were followed through 2013. ENT specialists and neurosurgeons referred 8 and 9 patients respectively, with the remaining 2 referrals from neurologists. Thirteen patients were not considered suitable for bevacizumab therapy at that time for several reasons. Four had complete bilateral deafness, eight had unilateral hearing loss with intact hearing in the other ear; one patient was excluded for logistic reasons, being resident in New Zealand.

Six adults were considered candidates for VEGF therapy, aged from 22 to 32 years

126 (mean 27 years, SD 4.7 years, Table 7.1). Three were resident in NSW; one patient each came from Queensland, Western Australia, and South Australia. Indication for therapy was primarily hearing loss, with several patients having brain stem compression, and 1 patient with spinal cord compression and back pain (Table 7.3).

Patient population: Children Fifteen children with a diagnosis of NF2 attended Neurogenetics Clinic from 2009- 2015. A detailed assessment of disease characteristics of these children is presented in Chapter 6). 2 children aged 12 and 13 years were included here (Table 7.1). The indication for bevacizumab treatment was hearing loss in both cases, although both children had additional disease related problems that were potential targets for therapy, to be monitored in follow up.

Disease Characteristics All but one patient had sporadic disease. Genotypes are shown where available, along with inheritance pattern (Table 7.1). One of the children had an atypical phenotype for NF2, with NF2 deletion identified on CGH microarray performed for investigation of developmental delay and spasticity (patient 8).

Age at onset of symptoms referable to NF2 ranged between 5 and 22 years (mean 13.6y, SD 5.8y). Diagnosis was made in late adolescence or early adulthood for most patients within 12 months of initial symptoms. Two patients experienced NF2 associated symptoms for 2-3 years prior to diagnosis.

Most patients experienced clinical problems in multiple domains. Hearing impairment affected 8/8, ranging in severity. Vision was affected in 4/8, with unilateral functional blindness in one child; a single adult had significant daily functional visual difficulties due to bilateral visual impairment. Four adults and one child experienced pain (headache, backache or neck pain) on at least a daily basis. All patients were independently mobile. However, three adults experienced daily dizziness, and two reported falls on a daily basis. Significant gait difficulties atypical for NF2 were experienced by patient 8, which was multifactorial in nature (spasticity, dizziness, pain), associated with chromosomal deletion extending beyond the NF2 gene.

127 Table 7.1 Clinical characteristics at presentation / diagnosis and genotype of NF2 patients treated with bevacizumab Patient Age Genotype Inheritance Presenting symptoms Age (y) first Diagnostic Age (y) (Gender) (y) symptoms criteria Diagnosis 1 (F) 22 NA Sporadic Tinnitus, unilateral hearing loss; 13 Bilateral VS 13 unsteady, headache 2 (F) 23 [c.41_42delTC p.Leu14GInfsX34] Sporadic Multiple cutaneous schw; Foot 15 Bilateral VS 17 dropà ankle reconstruction 3 (F) 32 65688 G>A (IVS7-1 G>A) Sporadic Focal sensorimotor seizures 19 Bilateral VS 19 deln exon 8+inframe deln 45 aas (codons 226- 270); likely pathogenic 4 (M) 22 NA Familial Foot drop 10 Bilateral VS 10 5 (M) 32 [c.1627_1628del Sporadic Headache 22 Bilateral VS 22 p.Lys543 AspfsX21] (Hz) Blurry vision Frameshift->insertion prem stop codon Diplopia 6 (M) 31 [c.1336_1337del p.Arg446 GlufsX48] (Hz) Sporadic Diplopia à Meckel’s cave tumour 17 Bilateral VS 20 frameshift mutation exon 12àlikely on MRI àresection pathogenic; likely mosaic: 2 tumours, not in blood. 7 (M) 12 NA Sporadic Unilateral visual and hearing loss 5y VS 5 OPSM 8 (M) 13 22q12.1q12.2 Sporadic Developmental delay; Spasticity 8y CGH 8 (A_16_P03609081>A_16_P21309118) x1 ** NF2 specific: tinnitus, hearing loss Bilateral VS

*For sporadic cases only; familial cases identified pre-symptomatically with surveillance; ** Chromosome 22 deletion detected on CGH microarray including the NF2 gene. This patient presented with clinical features likely secondary to the larger deletion; aas-amino acids, CGH-chromosomal microarray, deln- deletion, IC-intracranial, ONSM-optic nerve sheath meningioma, NA-not available, prem-premature; schw-schwannoma, VS-vestibular schwannoma, y- years.

128 Impact on community participation was common in adults, including difficulty in vocational training or the workplace due to hearing impairment in 5/6; 1/6 adults had resigned from employment due to NF2 associated morbidity, and 1/6 young adults had not been able to pursue desired vocational training. One adult was no longer able to drive due to visual impairment.

Hearing function is shown in Table 7.2. All patients except one had audiology results demonstrating progressive decline in PTA and SDS consistent with the known natural history of NF2 (data not shown).

An overview of radiologic disease burden indicates most patients had significant intracranial and intraspinal disease (Table 7.2). Vestibular schwannomas were the primary target lesion for bevacizumab therapy in seven patients. In contrast, patient 2 had a large trigeminal schwannoma, along with smaller bilateral VS and multiple large cervical presumed schwannomas causing cord compression. Patient 7 was treated for hearing loss associated with VS as the primary target tumour, along with monitoring of bilateral meningiomas, and enlarging schwannomas around the cervical cord, threatening cord compression.

Prior treatment is summarized in Table 7.3. All patients were receiving medical therapy despite their young age. Medications included anticonvulsants, analgaesics, antidepressant medication and intermittent steroids. Steroid side effects (weight gain, striae) were prominent in one patient. Seven individuals had undergone surgical treatment, ranging from 1- 6 procedures (mean 2.9).

Functional Status and Quality of Life Scores for the baseline NF2 symptoms questionnaire were available for all adults ranging from 20-48 (mean 34.5, SD 11.9; Table 7.4). For many patients, items such as bladder and bowel incontinence and constipation were non-contributory throughout the course of the study. For this reason, scores have also been reported with these items deleted.

129 Table 7.2a Major complications of NF2 in patients identified as candidates for bevacizumab therapy Patient Age Major clinical Eye findings Visual Acuity Radiologic features Other features Community (y) problems Participation

1 22 Decreasing hearing in ERM 6/9 bilat Unilateral VS with brain CALM Choice of only hearing ear stem compression Cutaneous schw vocational training Symptoms of brain Multiple small lesions Multiple spinal tumours stem compression along spinal cord Peripheral nerve Leg weakness schwannoma Depressed Peripheral neuropathy mood/anxiety

2 23 Foot drop ERM 6/9 6/45 Bilateral VS without Trigeminal schw, Nil known Generalised weakness brain stem compression IC ependymomas/schw due to neuropathy Large trigeminal Peripheral neuropathy Mild hearing loss schwannoma Multiple cervical schwannomas with cord compression Multiple other spinal schwannomas Large axillary mass 3 32 Hearing loss Post subcaps NLP 6/12 Multiple IC tumours Resigned from Altered voice cataracts Improved VA VS, ONSM (incl meningioma) Employment Weakness R/L optic 6/45 Apr 12 to Intracranial CALM Unable to drive Gait instability atrophy 6/12 Apr 13 meningioma Cut schw due to visual loss Intracranial after 16 months hypertension therapy Depressed mood

130 Table 7.2b Major Complications of NF2 in patients identified as candidates for bevacizumab therapy Patient Age Major clinical Eye findings Visual Acuity Radiologic features Other Community (y) problems features Participation

4 22 Hearing loss Post subcaps 6/9 6/45 Unilateral VS with Choice of vocational Visual loss cataracts (6/18 pinhole) brainstem training Gait instability (visual axis) compression Pain ERM SC 5 32 Hearing loss 2012 6/9 6/45 Unilateral VS with Impact on Peripheral Diplopia (R partial (6/18 pinhole) brain stem employment neuropathy CNIII due to R CNIII compression (upper and lower) schw) Gait instability Post subcaps Pain cataracts Depressed ERM mood/anxiety 6 31 Unilat anaesthetic 6/12 6/15 Unilateral VS Trigeminal Impact on cornea; without brain stem schw employment Corneal ulcer compression Peripheral scarring neuropathy

7 12 Hearing loss Bilateral optic nerve NLP 6/36 Bilateral VS Nil known Visual loss sheath meningiomas Bilateral ONSM Pain Cataract Cervical schw with cord displacement Other sp schw 8 13 Pain 6/12 6/12 Bilateral small VS Nil known Hearing loss Multiple spinal Gait instability schw Tinnitus CN=cranial nerve, ERM-epiretinal membranes, IC-intracranial, L-left, ONSM- optic nerve sheath meningioma, prn-as needed, R-right, SC-spinal cord, schw- schwannoma, subcaps-subcapsular, unilat-unilateral, VS-vestibular schwannoma, y-years.

131

Table 7.3 Previous management and indications for bevacizumab treatment Patient Age Medical Management Surgical Management Complications of Indication for (y) [total number] [total number procedures] management bevacizumab 1 22 Steroid Resection unilateral VS aged 15y [1] Unilateral deafness A*/ Brainstem Decreased lacrimation compression

2 23 Antidepressant Resection cutaneous schwannomas-multiple B** /Brainstem Analgesics prn Ankle reconstruction compression/ Laminectomy with resection spinal tumours (x3) [6] Cervical cord compression

3 32 Anticonvulsant Intracranial tumour resection (meningioma, unilat Unilateral CN VII palsy A VS, CN 10 schw) by 28y age [3]

4 22 Anticonvulsant Resection cutaneous schw Steroid side effects A Steroid [2] Foot reconstruction Partial CN VII palsy Radiation for unilat VS aged 15 years with stabilisation hearing [3]

5 32 Steroid Resection cutaneous schw Complete hearing loss; A / Brainstem Resection unilat trigeminal schw partial CN VII palsy compression Resection unilat VS [3]

6 31 Anticonvulsant Resection intracranial tumours (Meckels’ cave, unilat A VS, unilat trigeminal schw) [3]

7 12 Steroid Biopsy/resection optic nerve sheath meningioma [2] A

8 13 Analgesics (3) Nil B / Back pain *A= Decreasing hearing in only hearing ear; **B= Mild bilateral hearing loss; CN=cranial nerve, prn-as needed, schw-schwannoma, unilat-unilateral, VS-vestibular schwannoma, y-years.

132 Table 7.4 Baseline NF2 Symptoms Questionnaire scores and Linear Overall Wellbeing Scores

Patient NF2 Symptom NF2 Symptom Score Linear Overall

Score (Items X-Y excluded) Wellbeing Score (LOWS)

1 38 38 0.43 2 47 44 0.57 3 48 47 0.41 4 23 23 0.34 5 31 31 0.62 6 20 19 0.77

Mean (1-6) 34.5 0.52 SD 11.9 0.16

8 14 14 0.99

A single response was recorded in the open question only, so this was overall non- contributory. Scores for the LOWS among adults varied from 0.34 to 0.77 (mean 0.52, SD 0.16; Table 7.4).

A range of SSQ49 responses were observed for NF2 patients across the 3 domains (Table 7.5) for all individuals, along with mean scores for adults (as this tool is validated in the adult population only). NF2 scores were lower than in the Gatehouse and Noble cohort, consistent with expectation, as their patients had less severe hearing impairment compared with our patients who had unilateral complete deafness along with impairment in the remaining ear.

Mean scores for each domain in our NF2 patients were also lower than in population 2, suggesting greater disability in a population that included patients with sporadic VS or unilateral hearing loss of other aetiologies. Similarly, NF2 patients reported greater

133 auditory disability than in Population 3, which included some patients with preserved hearing on one side.

Table 7.5 SSQ responses for NF2 patients (shaded) and other hearing impaired populations

NF2 Patient/ SSQ Domain Population Speech Spatial Quality

1 1.00 0.88 2.72 2 4.29 3.12 5.06 3 2.86 2.53 5.33 4 1.21 1.18 0.89 5 0.86 0.88 3.11 6 3.86 3.86 4.78 7 7.43 7.88 9.33 Mean (Adults 1-6) 2.35 2.07 3.65 (SD) (1.52) (1.27) (1.72)

Population 1* 4.39 5.65 6.34 N=153 (1.35) (0.97) (1.32)

Population 2** 5.0 3.2 6.5 Cases N=58 (1.8) (2.0) (1.7) Controls N=49 4.5 3.3 6.7 (1.9) (2.1) (1.4)

Population 3*** 2.1 1.9 3.5 Contralateral HA N=9 (1.2) (1.0) (1.7) 3.9 3.0 5.8 Contralateral NH (1.4) (1.5) (1.5) N=11

*Original cohort of older adults reported using the SSQ (255); **Patients treated with bone anchored hearing aids, including some patients with sporadic VS; no significant difference between groups (260); *** Patients with unilateral sensorineural deafness of various aetiologies, prior to treatment with cochlear implantation having either normal hearing (NH) or a hearing aid (HA) on the opposite side (259).

134 Individual SF36 responses and means are shown in Table 7.6a for comparison with other populations (Table 7.6b). Our NF2 mean scores were reduced compared with Australian normative data for age-matched patients, and versus post-operative vestibular schwannoma patients. Greater similarity was seen with the UK population of NF2 patients. Confidence intervals were broad in the Australian cohort reflecting small sample size.

Discussion The group of patients selected for therapy with bevacizumab included predominantly patients in the young adult age range. The main reason for exclusion of older adults was significant pre-existing bilateral hearing loss.

These patients do not represent a population-based sample of NF2 patients, and as such cannot be compared directly with other population-based studies of impact of disease on individuals with NF2. However, this subset represents a group of individuals with progressive disease, requiring active treatment, likely with similarities to NF2 patients selected for bevacizumab therapy at other centres in recent years, using similar selection criteria.

At the time of initiating this study, consideration of cervical tumours as an indication for treatment deviated from use of VEGF inhibitors at other sites. While specific effects on hearing and tumour volume were clearly appropriate for 5/6 adults identified for systemic therapy for VS, we were cognisant of the possible benefits of systemic therapy for other schwannomas. In Patient 2, risks associated with progression of cervical disease were considered to warrant treatment alongside bilateral VS. This patient demonstrates the complexity/high disease burden seen in many cases and highlights the challenges of monitoring outcomes in a complex systemic disease such as NF2. For this reason, a generalized symptom checklist was designed to monitor for change in multiple items, along with a simple overall measure of quality of life using the linear scale (LOWS), and SF36.

The eight patients described in detail here were heterogeneous in terms of disease burden, and active medical problems. Disease-related morbidity was significant, with

135 Table 7.6a SF36 responses for NF2 patients

PATIENT PhysFxn RolePhys Pain Gen Hlth Vitality Social RoleEmtl Mental Hlth LimPhysHlth En/Fatigue LimEmtlHlth EmtlWellbeing

1 65 0 22.5 20 20 50 33.3 56

2 5 25 55 50 65 75 100 88

3 5.6 0 67.5 0 10 0 33.3 56

4 65 0 55 50 60 62.5 0 64

5 70 0 32.5 37.5 50 50 0 48

6 100 75 100 85 80 62.5 100 84

7 95 100 90 95 80 100 100 96

8 45 50 77.5 35 45 50 66.7 76

Mean* 51.8 16.7 55.4 40.4 47.5 50.0 44.4 66.0 (SD) (38.3) (30.3) (27.4) (29.1) (27.2) (26.2) (45.5) (16.3)

*Mean of adult patients 1-6.

136 Table 7.6b Mean (SD) SF36 responses for Australian NF2 patients, and comparative populations

Population PhysFxn RolePhys Pain Gen Hlth Vitality Social RoleEmtl Mental Hlth LimPhysHlth En/Fatigue LimEmtlHlth EmtlWellbeing

Aust* 51.8 16.7 55.4 40.4 47.5 50.0 44.4 66.0 (38.3) (30.3) (27.4) (29.1) (27.2) (26.2) (45.5) (16.3)

NF2UK** 40.1 41.2 45.8 38 42.6 40.1 40 41.9 (14.5) (12.3) (13.3) (12.2) (11.1) (11.8) (14.7) (13.1)

VS*** 76.2 63.78 74.35 67.13 61.41 78.44 77.55 75.51 (28.07) (43.71) (26.50) (25.57) (22.87) (27.86) (35.09) (19.32)

Aust Norm‡ 93.3 82.8 80.8 79.2 64.6 87.5 85.6 77.8

*Australian NF2 adults 1-6; **Manchester NF2 adults, N=62 (263); ***Australian postoperative QOL in VS patients (N=98, mean age 55y, range 10-77y) (261); ‡Australian normative values of 25-50 year olds, combined genders (147).

137 all adults experiencing daily functional limitations. Most required regular or intermittent medical therapy, and several had adjusted life goals/community participation/employment due to their disease. The negative impact of NF2 on daily activities including work, and social interaction has been identified as a key finding in other studies of adults with NF2 (245, 264). In a study of 62 adults (mean age 39y, mean age of NF2 diagnosis 28y), 28% of adults were unemployed due to NF2, and an additional 15% had taken early retirement on medical grounds(265).

Multiple surgical procedures had been performed with some complications but overall benefit based on general clinical assessment in our patients. As effective systemic medical therapies become available, it is likely that the timing and nature of surgical intervention will change in the future.

Overall, patient-reported outcomes (PROs) demonstrated a range of responses among individuals, with clustering of higher or lower scores consistently in any one patient across different assessment tools. Scores in the two children included demonstrated fewer symptoms and functional limitations than in adults. One child has atypical NF2 as part of a larger chromosomal deletion, and thus, his functional impairments do not reflect isolated NF2 related morbidity. The other child with severe disease resulting in unilateral deafness and blindness demonstrated remarkable resilience on patient reported measures, suggesting adequate functioning of the remaining sensory systems to prevent significant functional impairment. It should be noted that this questionnaire was administered partway through VEGF therapy for this child only (following cessation and prior to restarting therapy), so represents partially treated status rather than naïve pre-treatment responses. As such it may reflect positive response of prior therapy.

The NF2 symptoms questionnaire yielded variable scores for different patients, depending on clinical presentation, such as frequency of pain. In general, symptom scores appeared to correlate with other PROs, suggesting the NF2 symptoms questionnaire may be useful for stratifying functional status in NF2 patients (correlation based on statistical testing not possible). Use in a larger patient group would be needed to assess this further. In addition, scoring responses in normal individuals versus NF2 patients would be helpful to further validate this tool as

138 specific for identifying relevant NF2 symptoms, with the expectation that scores would cluster across non-overlapping ranges for the patient and general population groups. The open question was not useful, possibly due to the comprehensive nature of other questions included. Of note, items in this questionnaire assessed physical functioning only, leaving psychosocial factors unaddressed. The Linear Overall Wellbeing Scale (LOWS) is expected to reflect other such features.

The range of scores observed for the LOWS was generally aligned with other PRO measures. Although linear analogue scales for overall quality of life contain limited information, such scales have been used in assessing response to therapy for cancer patients, and have been found to correlate with other measures of treatment efficacy and quality of life (266, 267). Simple linear analogue scales likely have greatest value for populations limited in ability to complete longer instruments or when use of a simpler scale is warranted (267). Most patients in this study completed questionnaires without difficulty, suggesting young NF2 patients have the capacity to use detailed tools. However, follow up data was incomplete for some individuals (see Chapter 8), which may reflect that the multiple questionnaires utilized here proved onerous for others. In principle, PRO tools should include items sensitive to change over time, with minimal overlap between items, and the fewest items possible to detect change ie, removal of redundant items, as has occurred with refinement of the SSQ over time (see below). Utility of the NF2 LOWS will be assessed further in the next chapter compared with other PRO after treatment with bevacizumab.

Regarding disability associated with hearing impairment, SSQ responses in our patients revealed greater difficulties than in older adults with age-related hearing loss, and individuals with hearing loss due to other aetiologies, including sporadic VS. This is probably due to the nature of NF2 associated hearing loss, which becomes profound, and bilateral in most cases. In addition, these NF2 patients were selected due to severe disease, with inclusion criteria of predominantly unilateral deafness with progressive hearing loss in the remaining ear.

An alternative simplified tool, the SSQ12 (published since this study was conducted), may be useful to consider in future NF2 trials(268). The SSQ12 has the potential advantage of use for interview style administration in children older than 10 years, and for parents and teachers of children 5 years and older (268, 269). A comparative

139 study of the new SSQ12 versus SSQ49 for NF2 patients would be of interest to assess whether the shorter tool yields equivalent data and could be used in preference.

SF36 responses for our small cohort demonstrated reduced quality of life compared with the normative Australian population, with broad confidence intervals due to small sample size. Responses more closely resembled the Manchester NF2 population (Table 7.6). Interestingly, role limitations due to physical health and social functioning showed the greatest differences compared with healthy norms, as was found previously in post-operative VS patients (261). In contrast, another study of quality of life in postoperative sporadic VS showed 7/8 domains affected (excluding vitality)(270).

In considering clinical trial design, it is important that outcome measures are clinically relevant. In NF2 as a tumour suppressor syndrome, assessment of tumour volumes has been an obvious focus. A recent study assessed correlation of overall tumour burden measured using 3D volumetry on WBMRI in NF1, NF2 and schwannomatosis, demonstrating an association between overall tumour burden and bodily pain on SF36 in schwannomatosis and NF2, with other domains not significantly affected. We agree with the authors’ emphasis on monitoring psychosocial outcomes in addition to tumour volume, as tumour volume may not be directly associated with quality of life (187). Whether specific tumour volumes (eg. VS) may correlate with change in quality of life in response to treatment is a question which can be explored further in our study and others.

Other recent data supporting the potential utility of the SF36 as a useful clinical trial PRO measure in NF2 comes from the work of Neary and colleagues, who established hearing, balance, visual problems and psychosocial issues as being the most important concerns for adults with NF2 (N=62, mean age 39, mean age diagnosis 28y)(265), and provided evidence that SF36 responses are associated with communication, balance, and hearing difficulties in these patients(263).

A number of factors suggest our NF2 cohort represents a subset of severely affected individuals with NF2. Referral bias is likely, and younger age at onset of symptoms is typically associated with more severe disease. Severity of disease in NF2 is known

140 to vary depending on inheritance pattern and genotype, with familial cases and truncating mutations often manifesting with earlier onset, more severe disease (241, 271). Genotypes were available for only a proportion of patients, reflecting local practice of expectant management of NF2 due to resource limitation for genetic testing. In our setting, genetic testing is typically arranged to facilitate prenatal testing or to assist in the diagnosis of pre-symptomatic potentially-affected children.

The economic implications of NF2 have not been considered in this study. However, these descriptive data would inform a cost effectiveness assessment for bevacizumab in NF2. It is anticipated that disease related costs would be significant, and extend to experiences of family members. The impact of NF2 on family members providing such support has been acknowledged by affected patients previously(245). In this cohort, all but one patient attended appointments with a close family member for practical and social/psychological support.

Conclusion NF2 is a heterogeneous condition with variable age of onset and severity. Individuals with the condition are at risk of significant morbidity, disability and early mortality, due to the “biologically malignant” nature of NF2 associated “benign” tumours. Young adulthood is a key stage for many individuals when systemic therapy may be useful. NF2 presenting in childhood is often associated with a severe phenotype and may require systemic therapy earlier.

Patient reported outcomes should be considered where possible in NF2 treatment trials, assessing specific functional domains, along with measures of quality of life. The NF2 symptoms questionnaire and LOWS may be helpful during routine surveillance of complex NF2 patients, and possibly in systemic treatment trials. SSQ responses indicated significant disability associated with hearing impairment in this pre-selected cohort of NF2 patients compared to other populations with hearing loss. The SF36 offers a good general assessment of QOL, and showed pronounced disease impacts in NF2.

141 Chapter 8. Bevacizumab for Vestibular Schwannomas in Neurofibromatosis type 2

Introduction Vestibular schwannomas are the hallmark lesion in individuals with NF2, typically occurring bilaterally, and affecting 95% of individuals. These tumours cause headaches, tinnitus, hearing loss, dizziness and gait instability, and risk of early mortality due to brainstem compression estimated at up to 60% by the age of 44 years in one report (191). About 20% of patients with NF2 present with symptoms before the age of 15 years, and of these, up to 43% may have symptoms associated with vestibular schwannoma (10). Unfortunately, increased morbidity is associated with these tumours among individuals with NF2 compared with patients with sporadic vestibular schwannoma (in the absence of NF2), which is, in part, due to an increased growth rate of tumours in NF2.

Until recently, surgery and radiosurgery have been first line treatment approaches. Surgical treatment can be associated with risk of further hearing loss and damage to the trigeminal and facial nerves. These complications occur at a lower rate with gamma knife stereotactic radiosurgery (272, 273). Malignant transformation can occur rarely, and has been reported after radiosurgery (274). Patients with NF2 are at increased risk of radiation-induced malignancy compared to those with sporadic disease (189). For this reason, they may be excluded from treatments such as gamma knife stereotactic radiosurgery. While surgery and radiation treatment may decrease the size of tumours and associated symptoms of brainstem compression, these treatments do not typically yield improvements in hearing. Effective alternative medical treatments are needed for vestibular schwannomas, to prevent the morbidity associated with hearing loss and symptoms of brainstem compression. Furthermore, medical approaches for patients with complications of NF2-associated tumours are desirable because many patients experience morbidity from multiple tumours in the central and peripheral nervous system over time. As such, systemic therapy may deliver off-target tumour responses yielding significant clinical benefits (see Chapter 9).

142 Angiogenesis inhibitors such as bevacizumab (Avastin) have been recognised as important therapeutic agents for tumour management (23, 275), and have shown promise as therapy for vestibular schwannomas in NF2(37, 227, 228, 249). Bevacizumab is a monoclonal IgG1 antibody that binds to and inhibits the activity of vascular endothelial growth factor-A (VEGF-A). The goal of treatment with bevacizumab, via effects on tumour vasculature, is to reduce the size of vestibular schwannomas and to improve hearing loss and / or symptoms of brainstem compression in patients with NF2. Reduction of tumour growth rate and stabilisation of hearing function may constitute treatment response on a background of progressive growth and loss of function. As systemic therapy, this agent also has the potential to improve functional outcomes via effects on other tumours.

In recent years, significant consideration has been given to identifying appropriate outcome measures for use in clinical trials for the NF2 population (22, 23, 124, 214), with a focus on hearing and radiologic response of vestibular schwannomas.

In this chapter, I present in detail the response of the first Australian NF2 patients treated with bevacizumab, as well as a comparison with the growing international experience. Outcomes of interest included audiologic functioning and radiologic response of vestibular schwannomas, along with selected secondary tumours in some patients. Other patient-reported outcomes included physical symptoms measured with a novel NF2 symptoms questionnaire and simple overall wellbeing score, in addition to hearing disability measured using the SSQ49, and quality of life according to the SF36 questionnaire. Medication tolerability was also assessed and reported here.

Methods A prospective audit of bevacizumab treatment for vestibular schwannomas causing significant morbidity (hearing loss and symptoms of brainstem compression) was conducted in children and adults with NF2, followed at the Children’s Hospital at Westmead, and Westmead Public Hospital in Sydney between 2009-2013(200). The local Human Research Ethics Committee approved this study (10CHW14).

143 Patients Patients were evaluated in the Neurogenetics Clinic at CHW or Oncology Clinic Westmead, and met clinical criteria for NF2 (200). Recruitment from other centres around Australia was undertaken to increase medication availability for patients and to facilitate centralised review of efficacy and tolerability. Participating institutions included three sites in NSW (Prince of Wales Hospital, Randwick; Liverpool Hospital; Royal Prince Alfred Hospital, Camperdown), Perth (Hollywood Private Hospital, Nedlands, Western Australia), Adelaide (Flinders Medical Centre, South Australia), and Queensland (Haematology and Oncology Clinics of Australia, Gold Coast Cancer Centre and Day Hospital). This series includes Patients 1-7 from Chapter 7, and excludes Patient 8 due to incomplete outcome data.

Patients selected for bevacizumab treatment had either hearing loss documented in both ears or in their only hearing ear, and/or symptoms of brainstem compression. All treated patients had symptomatic vestibular schwannomas identified as the target lesion.

All patients were screened prior to treatment for factors that would increase risk of side effects from bevacizumab including uncontrolled hypertension, history of stroke, cardiac or peripheral vascular disease, deep vein thrombosis, known personal or family history of coagulopathy, hepatic dysfunction (parameters 2-3 x upper limit of normal for age), renal dysfunction (serum creatinine greater than 1.5x upper limits of normal for age) or haematologic dysfunction (absolute neutrophil count of less than 1,000, haemoglobin of less than 9 g/dl, or platelet count less than 100,000). No patients were pregnant or breast feeding during treatment. Advice was provided to females of reproductive age to use contraception and avoid pregnancy during treatment. In addition, based on animal data, alerts from oncology trials (CABARET), and observed changes in menstruation among our treated patients, advice was provided regarding potential effects of bevacizumab on fertility. Referral to fertility experts was recommended and arranged, to assess management options. No patients had prior exposure to Avastin, or other anti-angiogenic agents. One patient received prior chemotherapy, and one patient received a combined chemotherapy regimen during treatment with bevacizumab.

144

Patients were assessed with clinical evaluation, audiology, neuroimaging, and functional assessment questionnaires at baseline then at 3, 6, 12, 18, 21, 24 and 30 months on the Westmead campus where possible, alongside local treating oncologists who administered, and monitored therapy.

Bevacizumab therapy – Funding and Medication Administration As bevacizumab was not licensed for use in NF2, and not funded for this patient group, individual applications were made to the Drug Committee of the eligible patient’s Area Health Service for assistance in the provision of medication. Information was also provided to individual patient medical insurance companies outlining the rationale for treatment, and requesting financial support. Application was made to Roche Pharma for discounted medication for use in this study based on a cost sharing arrangement (one free dose for every three purchased doses).

Bevacizumab was administered as a fortnightly infusion (5mg/kg/dose), or 7.5mg/kg/dose every three weeks (Patient 3 only). Dose adjustment (pause in therapy or reduction in dose) was considered in the event of adverse effects of medication (Appendix 8). Bevacizumab was ceased prior to elective surgery or other therapy.

Evaluation of disease progression/efficacy of treatment Outcomes were divided into primary and secondary categories. Primary outcomes of hearing response and radiologic vestibular schwannoma response assessed at 3, 6, 12, 18, 24 and 30 months after commencement of treatment, in line with published recommended outcomes for use in clinical trials for treatment of vestibular schwannomas available at that time (22). Selected readily measurable non-vestibular intracranial tumours were also assessed. Symptoms, functional status and quality of life were assessed as secondary outcomes (described in detail in Chapter 7).

Baseline pre-treatment evaluation consisted of comprehensive medical assessment, audiology assessment and 3D volumetric cranial MRI (including thin slices (3mm) through the internal auditory canal) and cranial MRA, as well as whole spine, within 6

145 weeks of commencement of treatment with bevacizumab, and administration of questionnaires.

Primary Outcome: Hearing Audiology evaluations were performed in the audiology department CHW, Hearing Australia, (Chatswood and Hurstville) and at local audiology centres for out-of-state patients, based on a recommended protocol, with a view to standardisation across centres and time.

Speech discrimination score (SDS) was used as the primary audiologic outcome measure. SDS is a clinically relevant measure of speech discrimination proposed as a primary hearing endpoint in clinical trials for vestibular schwannoma in NF2 (22, 214), disproportionately affected compared with pure tone thresholds in patients with vestibular schwannoma and NF2. This was measured using a 10-item monosyllable word list, yielding a result ranging from 0 to 100%.

Hearing response was defined as improvement in SDS over baseline, meeting criteria for statistical significance at the P=0.05 level, according to published methods (22, 276, 277). This approach allows the number of pre- and post-treatment correct responses to be compared for each individual. The significance of changes in SDS compared with baseline was evaluated using published binomial confidence intervals (Critical Difference Values based on Binomial Distribution of Arthur Boothroyd and Carol Mackersie; Appendix 9)(278). This approach reflects the fact that the degree of change required for statistical significance depends on the initial deficit.

Primary Outcome: Tumour Volume Recommendations for imaging were provided to outside radiology institutions to optimise/standardise image quality across centres and for longitudinal measurements (Appendix 1). Vestibular schwannomas were chosen as primary target lesions, and followed for evaluation of change in tumour size over time. Secondary tumours were selected in some cases, to monitor response of non-vestibular tumours (intracranial schwannoma or meningioma).

146 Tumour size was assessed using three-dimensional volumetric analysis. Pre-treatment tumour growth rate was calculated where possible. Volumetric analysis was performed by the NFtumormetrics Group, Medical Imaging Centre, Massachusetts General Hospital, Boston. In addition, selected scans were reviewed using an alternate approach, by two radiologists at Westmead Hospital, to assess variability between methods (detailed in Chapter 9). Radiologic response was determined by changes in three-dimensional tumour volume compared with baseline volume and defined as follows; radiologic response: ≥ 20% reduction in tumour volume; stable disease: <20% change in volume; progressive disease: ≥ 20% increase in tumour volume according to recommended parameters for NF2 tumours (124).

Secondary Outcomes: Hearing Hearing was also described pre- and post-treatment using combined results of speech discrimination (SDS) and pure tone audiometry according to the classification system of the American Academy of Otolaryngologists-Head Neck Surgery (AAO-HNS) (279), with Class A and B representing functionally useful hearing. Pure tone thresholds were included in routine audiologic evaluation, and reported as minimum decibels heard over a range of individual frequencies, then averaged to represent the “pure tone average” (PTA; 500Hz, 1kHz, 2kHz, 4kHz). An audiometer detecting increments of 1-2dB (instead of 5dB) was used where possible to increase the sensitivity of this test. Minor hearing response was defined as an improvement in the pure-tone average of ≥ 10dB in the setting of stable speech discrimination scores with reference to baseline pure tone averages. Change in AAO-HNS hearing class over time was assessed.

Secondary Patient Reported Outcomes: Symptoms, Hearing Disability and Quality of Life Functional assessment tools utilised as secondary outcome measures have been described in detail along with baseline functional status of treated patients (Chapter 7). Secondary outcomes included functional measures based on questionnaire surveillance of symptoms (using the NF2 Symptoms Questionnaire, Appendix 6), hearing disability (SSQ49, Appendix 7), and quality of life (Linear Overall Wellbeing Scale-LOWS, Appendix 6; SF36 Appendix 4), scored at baseline (0), 3, 6, 12, 18, 21,

147 24 and 30 months of treatment when possible. Longitudinal change in the mean SF36 scores over time were analysed using repeated measures analysis of variance. A probability level of <0.05 was considered statistically significant.

Secondary Outcomes: Adverse Events Laboratory studies were monitored over time (≥ 3 monthly) including electrolytes, (Na, K, bicarbonate, urea, creatinine, calcium, phosphate, glucose), liver function tests (ALT, AST, bilirubin, albumin), coagulation profile (PT, APTT), and urinalysis. Adverse events/medication toxicity were categorized according to the Cancer Therapy Evaluation Program Common Toxicity Criteria Version 4.0 (280).

Treatment for VS as the target tumour was considered effective in the presence of radiologic response (≥ 20% reduction in tumour volume), and stable or improved hearing, or stable/ improved symptoms of brainstem compression (in cases where no functional hearing was present at baseline).

Results Patients, Target Tumours and Treatment Overview Three females and four males were treated, ranging in age from 13.8 years to 33.4 years (mean age 25.9y, SD 7.2y, Table 8.1). The primary indication for treatment was hearing loss. Several patients also experienced symptoms of brainstem compression at baseline (Patient 1, Patient 2, Patient 5, Table 8.1). In one patient (Patient 2) with moderate hearing loss, a large trigeminal schwannoma contributing to brainstem compression was assessed (Figure 8.1, 8.5). This patient also had large bilateral cervical schwannomas with the potential to cause significant morbidity, which were measured in a separate sub-study, and showed radiologic response (see Chapter 9). Patient 4 had two intracranial meningiomas, and Patient 7 had 2 optic nerve sheath meningiomas followed in addition to bilateral VS. Patient 5 received chemotherapy (Imatinib) for 5 months prior to bevacizumab. Imatinib was ineffective and caused gastrointestinal toxicity (nausea and vomiting).

148

Table 8.1 Characteristics of patients treated with bevacizumab

Patient Age at Indication for treatment Hearing Ears VS measured Other tumours (n=5) Avastin* treatment measured (n=9) (n=13) (months) (years)

1 23.0 A †/Brain stem compression R 1 30

2** 23.8 B ††/ Brain stem compression R / L 2 Trigem schw (1) 30+ 3 33.0 A L 2 Intracranial Men (2) 18+ 4 22.8 A R / L 2 18+ 5 31.5 A/ Brain stem compression L 2 9+ 6 33.4 A L 2 6+ 7 13.8 A L 2 ONSM (2) 9+

Mean (SD) 25.9 (7.2) Total 9 13 5

* Treatment interruptions common due to funding, variations in patient follow up, other medical indications (Patients 3,4,5,6,7; see Figure 8.2) ** Additional tumours studied in a separate sub-study (Chapter 9); Men-meningioma, ONSM-optic nerve sheath meningioma, Trigem schw- trigeminal schwannoma; † A-Decreasing hearing in only hearing ear; †† B-Mild bilateral hearing loss; CN-cranial nerve, prn-as needed.

149

a b c

Figure 8.1 T1 fat saturated gadolinium enhanced MRIs showing vestibular schwannomas (thin white arrows) and other tumours followed with 3D volumetric analysis; a. bilateral vestibular schwannomas and large left trigeminal schwannoma (thick white arrow; Patient 2, axial view); b. left vestibular schwannoma, right parasagittal (thick black arrow) and left posterior frontal meningiomas (thin black arrow; Patient 3, coronal view); c. bilateral vestibular schwannomas and large optic nerve sheath meningiomas (thin black arrows; Patient 7, axial view).

150 The child included in this series (Patient 7) experienced significant complications of NF2, including unilateral deafness and blindness by 5 years of age. NF2 tumours of concern included large bilateral optic nerve sheath meningiomas, small but growing bilateral VS, and cervical schwannomas. Selected tumours are illustrated in Figure 8.1.

Bevacizumab was provided with a view to reducing risk of disability due to these lesions, with VS selected as primary tumours to follow, and selected non-vestibular schwannomas or meningiomas as secondary tumours for radiologic measurement.

Clinical follow up occurred between 6-30 months (mean 22.86 months, SD 8.78). Radiologic and audiologic data were available for variable time points for different individuals.

Bevacizumab Supply and Administration Details regarding supply of medication are summarised in Appendix 10. For this study, duration of treatment ranged between 6-30 months (median 15.8 months), although treatment was continued for a longer duration in a number of cases. Six patients received medication funded by the local area health drug committee, with a cost sharing arrangement negotiated with Novartis Pharma. The duration of public funding varied from 4 months to 26 months. Indefinite funding was not available in any case, despite evidence of clinical benefit. After 26 months, one patient elected to cease therapy, being unable to self-fund extended treatment (estimated cost of $20,000 per annum), and proceeded to vestibular schwannoma resection (Patient 1). One patient self-funded medication for at least a period of 9 months following withdrawal of public funding, in circumstances where subjective hearing improvement occurred and tumour volume remained static (Patient 6). In one case, public funding was granted following a period of self-funded treatment showing positive response (Patient 3). One patient received financial support from the private health insurer from commencement of treatment (with cost sharing arrangement with Novartis Pharma), and received donated funds from community fundraising to cover costs of follow up visits to Sydney (P2). Bevacizumab was funded by the private health fund (in a cost sharing arrangement with Novartis Pharma) after demonstrated

151 response to therapy in another case (Patient 4, following re-treatment response). Overall three patients self-funded treatment for periods ranging between 6 to 12 months, (either at commencement of treatment or following public funded therapy), representing a significant personal financial burden.

Patients were generally treated with 5mg/kg/dose fortnightly infusion (5 of 7 patients). Patient 3 received 7.5mg/kg/dose three weekly infusion. Patient 7 was the first treated in this cohort, commencing at 15mg/kg/dose, reducing after 10 months to 5mg/kg/dose. In Patient 7, the first nine months of bevacizumab treatment overlapped with treatment with a somatostatin analogue. The somatostatin analogue was prescribed as the patient had progressive optic nerve meningioma and visual loss in his one seeing eye, and there was evidence of potential benefit (281). The meningioma was subsequently treated successfully with radiation therapy and the somatostatin analogue ceased . Breaks in bevacizumab therapy occurred to monitor disease progression off treatment, to accommodate other modes of therapy, and in one case due to adverse events (Patient 4), as shown in Figure 8.2.

Primary and Secondary Outcomes-Hearing Hearing was measurable in nine ears. Baseline hearing function is shown for each patient for SDS (Table 8.2), pure tone audiometry (PTA) and American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) hearing class (Table 8.3, Figure 8.3). Speech discrimination scores at multiple time points were available for 5 patients (follow up ranging between 6-30 months) showing increased scores over time. However, statistically significant change in this measure was not demonstrated in any case. A trend toward sustained improvement was suggested in Patient 2 and Patient 3, at last follow up (30m and 18m respectively). One additional patient (Patient 1) showed improvement approaching a significant level. Table 8.2 shows the speech recognition score required to accept the difference as statistically significant with 95% confidence using 10 items, and using 25 items. Use of a larger number of items potentially facilitates demonstration of significant change over time, with modeling using extrapolation of this data.

152 Pre-baseline pure tone audiometry (PTA) data were available for 4 patients, showing clear increase in PTA in 3 patients prior to therapy consistent with progressive disease. On bevacizumab, four patients showed definite decline in PTA, with a drop of >20dB observed in 3 patients. The tendency to maintenance of stable PTA is evident, in contrast with progressive increase typical in untreated NF2. However, the response was not sustained in all cases, with considerable rise in PTA in Patient 2 (left ear) over time despite medication (Figure 8.3).

Figure 8.2. Overview of patient treatment with bevacizumab, including breaks in therapy.

153 Table 8.2 Speech discrimination scores for Patients 1-6 over time during treatment (AB 10-word lists), including model of effect of increasing number of items (phoneme scoring, 25 items per list) Word List Word list Phoneme Phoneme Patient Months (10 items) p<0.05* Model Scoring (25 items) †* Model 0 3 6 12 15 18 24 30 p<0.05***

1 78 63 65 70 94 80 84 NS ≥98 S ≥87

2 94 97 94 100 100 NS Ceiling** NS Ceiling

3 86 90 100 97 NS Ceiling S 100

4 84 100 100 NS Ceiling S 100

5 40 - ≥83 ≥68 -

6 70 75 NS Ceiling NS ≥92

*Speech discrimination score required for significant difference at 95% confidence level using 10-word list (10 items). **Ceiling effect (SDS ≥68 using 10-word list ie. even 100% is not significantly different). *** Speech discrimination score required for significant difference at 95% confidence level using phoneme scoring (2.5x10=25 items). This models the effect of increasing number of items on which each score is based. Listed scores represent improved performance at 95% confidence level. †Extrapolation of this dataset, to model result using phonemes (increasing to 25 items); AB=Arthur Boothroyd; NS=not significant; S=significant.

154

Table 8.3 AAO-HNS Hearing Class pre- and post-treatment with bevacizumab

Patient Baseline Post- ≥ 10 dB treatment* decrease PTA PTA SDS Class PTA SDS Class 1 65 78 C * 46 84 B * Yes 2 46 94 B 43 100 B No 50 86 B * 83 97 C * No 3 39 84 B 49 100 B No 4 119 0 D 83 6 D Yes 85 40 D 63 30 D Yes** 5 41 60 B 6 74 70 C 85 70 C No 7 31 21 Yes

* Best result; ** not sustained beyond 3 months; AAO-HNS-American Academy of Otolaryngology-Head and Neck Surgery, dB-decibels, PTA-pure tone audiometry, SDS-speech discrimination score.

155

Figure 8.3 Pure tone averages (PTA) over time, pre- and post- bevacizumab treatment.

156 The AAO-HNS Hearing Class grades pre- and post-treatment showed change in hearing class following treatment for Patient 1 (improvement) and Patient 2 (decline in hearing function in one of two ears coincident with ear infection, without recovery over time), with other ears remaining in the original class (Table 8.3).

Primary Outcome-Tumour Volume Pre-treatment vestibular schwannoma MRIs were available for 9 tumours in 5 patients, with annual growth rate estimates ranging between 8.7-105% as shown in Figure 8.4 (Mean 56.2%, SD 41.1). Radiologic follow up ranged from 6 to 36 months (mean 20.1 months, SD 12.2).

Thirteen VS were followed with baseline tumour volumes ranging from 0.36 to 25.34ml (mean 7.35, SD 7.50). Five readily measurable non-vestibular tumours were selected for follow up in this study, including a large trigeminal schwannoma contributing to brainstem compression (Patient 2), two optic nerve sheath meningiomas (clinically significant, associated with unilateral blindness and risk of visual loss on the opposite side, Patient 7), and two other readily measurable intracranial meningiomas (which may have contributed to risk of seizures in a patient with history of epilepsy; Patient 4, Figure 8.1). The trigeminal schwannoma was the largest lesion (range 1.58-43.05ml; mean 21.77, SD 17.79).

On a background of typical progressive disease pre-treatment, clinical benefit was observed in 84% tumours (N=11) based on radiologic response and stable disease. Seven of 13 (54%) VS showed ≥20% volume reduction (ranging between 29-55% (mean=43.0%, SD 10.8%).

All adult patients had at least one VS showing volume reduction. However, neither VS in Patient 7 showed a significant radiologic response. Four VS (30%) showed relatively static growth (<20% volume reduction). Two VS (15%) showed progressive growth (increase of 83%, Patient 3; increase 56%, Patient 7).

Limited data were available regarding pre-treatment vestibular schwannoma growth rates (Figure 8.4). Those patients with clear pre-treatment growth (Patient 1,3,4,5)

157

Figure 8.4 Vestibular schwannoma volumes over time for each patient treated with bevacizumab.

158

tended to show tumour shrinkage with treatment. For Patient 7, pre-treatment growth was relatively static, with a less impressive response to treatment observed.

In terms of non-vestibular tumours, only the trigeminal schwannoma showed response (39% tumour shrinkage by volume; Figure 8.5). One of the two intracranial meningiomas in Patient 3 showed little volume change, while the other showed progressive growth exceeding 80% volume increase over 12 months. Both optic nerve sheath meningiomas (Patient 7, Figure 8.1, 8.5) increased by 11% volume during the first 9 months of treatment with bevacizumab and somatostatin analogue.

Figure 8.5 Non-vestibular tumour volumes over time during treatment with Bevacizumab.

159 Patient Reported Outcomes A. NF2 Symptoms Review Checklist/Linear Overall Wellbeing Scale (LOWS) The most robust data were available for patients 1-3 due to regular administration of the questionnaire at scheduled time points. These 3 patients showed improvement in symptoms review scores ranging from 3 to 18 points reduction between baseline and final measure (Figure 8.6). Considering post-treatment symptoms scores as a percentage of baseline, improvements ranged between 15-52%. Scores were reduced by ≥15 points in four patients.

For one of these (Patient 4), the score increased during the initial phase of therapy, then showed reduction (improvement) during a second uninterrupted phase of treatment. Significant psychosocial factors affected this individual during the early phase, and were more settled later. Two patients showed static responses (Patients 2 and 6; change in scores of 2-7 points only).

Figure 8.6 NF2 Symptoms Questionnaire Scores over time on bevacizumab treatment (≥15-point reduction in scores considered improvement).

160

Patients 2 and 3 showed improvement in symptoms of brainstem compression with treatment (headache, dizziness, nausea and vomiting; data not shown), paralleling the clinical impression during therapy. Pain improved for several patients with treatment. Other patients reported reductions in falls/unsteadiness, paresthesias and visual blurring. Symptoms that did not change with treatment included tinnitus, and speech difficulties. Bladder and bowel dysfunction were not prominent symptoms in this group.

Responses for the Linear Overall Wellbeing Scale generally paralleled the inverse of NF2 symptoms score for each patient (Figures 8.6 and 8.7) as expected. Improvements reported by patients 1-3, ranged between 15-37% above baseline. As such, the magnitude of change using this tool was lower than for the NF2 symptoms questionnaire.

B. SSQ responses SSQ49 results are shown in Figure 8.8. Subscales most affected were Speech and Quality. Two of five patients showed improved scores across all domains (Patient 2 and 5). One additional patient showed improvements in Speech and Quality domains (Patient 3). The magnitude of improvement tended to be highest for the Speech followed by Spatial domains. Patient 1 did not record consistent improved responses even though other tools indicated benefit from treatment (NF2 symptoms score, LOWS and SF36).

C. SF36 Quality of Life Responses SF36 response domains grouped into 2 clusters (physical and mental health) over time are shown in Figure 8.9. Overall, improved scores were seen in all patients during treatment across multiple domains (Patient 4 during second phase of treatment). Limits to physical functioning varied between extreme scores of 0-100 in some patients without demonstrating clear trends over time (Figure 8.9b). Overall, however, this domain and others within the physical health cluster tended to show improvement on bevacizumab therapy (including physical functioning, pain and general health). Similarly, domains within the mental health cluster tended to improve over time on medication.

161

Figure 8.7 Linear Overall Wellbeing Scale (LOWS) scores over time during bevacizumab treatment.

Interestingly, Patient 2 recorded high scores in mental health parameters (consistent with good quality of life), with minimal change over time, despite endorsing significant hearing disability on the SSQ questionnaire. This observation suggests social/emotional resilience in this individual.

Overview of Responses Table 8.4 summarises patient responses assessed using different outcome measures. Three patients showed hearing response (PTA criteria only), six showed vestibular schwannoma volume response (7/13 ears), and five of six assessable patients experienced variable symptomatic/quality of life benefits depending on the measurement tool.

162

Months

Figure 8.8 SSQ scores for each domain over time during bevacizumab treatment.

163

Figure 8.9 SF36 domain scores over time during bevacizumab treatment (a-d physical health; e-h mental health).

164 Table 8.4 Overview of Patient Responses during bevacizumab treatment Patient Major Hearing Minor Hearing VS Volume Other Sx LOWS SSQ SF36 Response Response ≥ 10 dB Response Volume (SDS) AAO-HNS decrease PTA Class 1 No Yes Yes Yes NA Yes Yes No Yes

2 No No No Yes Yes* No Yes Yes Yes No No No No (stable)

3 No No No Yes No** Yes Yes No Yes No (prog) No**

4 No No Yes Yes NA Yes*** No No*** Yes*** No No No Yes

5 NA NA NA Yes NA Yes No Yes Yes No (stable)

6 No No No Yes NA No No NA NA No (stable)

7 No NA Yes No (prog) No** NA NA NA NA No No** (stable)*

TOTALS 0/8 1/7 3/8 7/13 1/5 4/6 3/6 2/5 5/5 *Trigeminal schwannoma; **Meningioma; ***Improved symptom score during second phase of therapy only, SSQ responses not available for second phase; NA-not available, prog-progression, Sx-symptoms.

165 Adverse events Adverse events are shown in Table 8.5. No Grade 4 or 5 events were recorded. The most frequent events were fatigue and infection. Hypertension and proteinuria developed only in Patient 3 (aged 34y) during three weekly therapy, which was treated and infusions continued at a lower dose.

Table 8.5 Incidence of Adverse Drug Reactions and Laboratory Abnormalities according to CTCAE (Common Terminology Criteria for Adverse Events v4.0)

Event Grade 1 Grade 2 Grade 3 Patients Fatigue 4(ongoing) 4 Infection Dermatitis 1 1 Cellulitis 1 1 Otitis media 1 1 Otitis 1 1 externa Viral URTI 3 3 Viral 1 1 1* encephalitis Proteinuria 1 Hypertension 1 Seizure 1* Menstrual 2 2 irregularities (ongoing) Diarrhoea 1 1 (ongoing) Dizzyness 1 1 Shortness of 1 1 breath Depression 1 Haematemesis 1* Thrombotic 1* events** Stroke*** 0 Elevated LFTs 1 1 *Single hospitalisation; ** Peripheral venous thrombosis associated with intravenous line; *** Intracranial thrombotic/thromboembolic and haemorrhagic events; LFTs- liver function tests.

166 Menstrual irregularities were observed in this young population, coincident with information from the Cabaret Study (carboplatin and bevacizumab in recurrent glioblastoma multiforme) highlighting the risk of ovarian failure in women treated with bevacizumab. While this was of limited concern in patients recruited to the CABARET study, it is certainly of relevance in a young cohort of women with NF2. No women in this cohort elected to cease treatment with bevacizumab. However, advice was sought from fertility experts and pause in therapy occurred in one case to allow egg harvest and storage.

Treatment interruption due to adverse effects occurred in only one case. This involved hospitalisation due to haematemesis, viral encephalitis complicated by seizure, and thrombosis at an intravenous line site. Bevacizumab was ceased. Three months following recovery from this illness including thrombus resolution, progression of NF2-associated disease prompted reconsideration of bevacizumab. Medication was cautiously restarted with no significant recurrence of these events observed during 18 months subsequent therapy with the drug.

Informal long-term follow up At last known follow up according to correspondence from local treating specialists, six of seven patients remained on therapy (mean duration of treatment for adults with interruptions, 24.5 months (SD 6.69) and including the child, 29.6 months (SD 14.74)).

Treatment had been ceased and recommenced for six patients. The seventh patient discontinued bevacizumab and proceeded with surgical management. Interruption in treatment was due to funding problems in three cases. Hospitalization with encephalitis (as documented above), interrupted therapy in one case. Planned temporary discontinuation of bevacizumab occurred to allow egg harvest in one case and during radiotherapy in the other instance. Orbital radiotherapy was provided with good effect for progressive periorbital oedema associated with optic nerve sheath meningioma in Patient 7. During breaks in VEGF inhibitor treatment, gradual progressive growth of NF2 associated tumours was observed without significant rebound growth (data not shown).

167

Discussion As a treatment for NF2-associated schwannomas, bevacizumab resulted in clinically meaningful improvements in hearing, tumour progression and symptoms of brainstem compression and pain, with additional benefits across multiple domains in patient reported quality of life.

Hearing Response Overall, this cohort was similar to NF2 populations in USA(37, 228) and the UK(249), treated with equivalent doses of bevacizumab, and followed using standardised outcome measures for radiologic and hearing response. Radiologic response in our group (54% of VS) was generally comparable with these sites. However, we were unable to demonstrate primary hearing responses (SDS) matching the other patient series.

In the first report of NF2 patients (N=10) with symptomatic bilateral vestibular schwannomas treated with bevacizumab, decreased tumour volumes exceeding the 20 percent threshold were observed in 6 of 10 vestibular schwannomas, with statistically significant change in word recognition score (WRS) in four of seven assessable patients (57%)(37). Follow up data published 3 years later showed similar results in a larger group of 31 patients with radiographic response in 55% (17/31) of vestibular schwannomas and hearing improvement in 57% of evaluable patients (13/23, using 50 word lists)(228). In the subsequent UK report of 61 patients with progressive vestibular schwannomas, radiologic response using the same outcome measure (≥ 20% reduction in tumour volume) was similar to the results seen in our Australian cohort (39% of tumours demonstrated radiological response and 45% of patients had a hearing response (5/11)(249). In contrast to our patients, in the UK population, maintenance therapy was continued at a reduced bevacizumab dose of 2.5mg/kg fortnightly (249). Others centres have also used reduced doses with sustained benefit over time in order to minimise side effects(282).

A significant limitation of the study method utilised here involves the assessment of speech discrimination scores using Arthur Boothroyd word lists limited to 10 words,

168 which made it difficult to demonstrate significant change over time. This is because the variance in speech discrimination scores is related to the number of words presented, such that the upper and lower limits for the 95% critical differences (at probability level of p=0.05) for percentage scores are much broader when fewer words are presented (276). For the sake of modelling the impact of this effect, had multi-phoneme (polysyllabic) words been utilised (extrapolating from 10 to 25 items), the likelihood of a significant difference between scores with 95% confidence could be demonstrated in 3 of 5 patients, increasing the power of this measure. Based on the initial score derived from 10 word lists and the ceiling effect, only 2 of 6 patients in this study were eligible for a measurable hearing response. Only one patient had follow up data, approaching but not reaching a statistically significant score. In future, larger word lists should be used for monitoring hearing response in this population.

As alternative hearing outcomes, change in PTA (>10dB hearing level decrease in PTA) and change in AAO-HNS hearing class were also assessed here, since they have been used in other trials for NF2 patients, including bevacizumab (283), and the epidermal growth factor inhibitor, lapatinib(36). Change in PTA exceeding the 10dB hearing level threshold was seen in 57% (4/7) of our patients, and improved hearing class in 14% (1/7). This contrasts with a lower proportion response in a European study of 12 adults treated with bevacizumab, where 1 of 9 ears (11%) responded to medication according to the PTA threshold, and 1 of 13 ears (8%) improved in AAO- HNS hearing class; word recognition score showed greater improvement (23% ears; 3/13)(283). In the lapatinib study, no patients met the PTA improvement criterion, while 4 of 13 patients (31%) had significant increase in word recognition score (using 50 word lists)(36).

Radiologic Response The reason behind the variable radiologic responses in different vestibular schwannomas remains unclear. This limited dataset cannot shed light on this question, although among our patients, smaller, slower growing tumours (Patients 6 and 7) tended toward reduced responses compared with others. Morris and colleagues (United Kingdom) found that tumours with a higher baseline growth rate were more likely to show a radiologic response, and that younger patients tended to have less

169 radiologic response, although their tumours had higher growth rates(249). In contrast, Plotkin et al. (USA) assessed these features along with others including baseline tumour volume and hearing level, and did not identify any clinical feature consistently predictive of either radiologic or hearing response(228). However, increased intratumor oedema, blood flow and capillary endothelial permeability may be important. Association between these features as estimated by apparent diffusion coefficient on diffusion-weighted imaging, and contrast transfer coefficient on dynamic contrast enhanced MRI have correlated with tumour response and warrant further consideration (37, 248, 284).

There was significant tumour shrinkage in a trigeminal schwannoma contributing to brainstem compression in one patient, with additional shrinkage of cervical schwannomas as detailed in the following chapter. The observation that non- vestibular schwannomas respond to bevacizumab is not surprising given shared tumour biology. The potential benefit of treatment beyond vestibular schwannomas may be very important in some individuals. Other authors have reported clinical and radiologic effect on non-vestibular tumours including facial schwannoma(248), and spinal schwannomas associated with complete resolution of pain(285). In our series, no radiologic response was observed for meningiomas, compared to modest response of meningiomas to bevacizumab in other series(286). Alternative medications are needed for meningiomas in this patient group.

Patient Reported Outcomes One of the strengths of this study includes consideration of patient reported outcomes assessing hearing disability and quality of life, which demonstrated improvements during treatment. Addition of QOL assessment is expected to capture some of the added benefits to patients from systemic therapy beyond hearing and tumour size (such as pain). We are not aware of any other patient reported tool used to date to assess detailed functional changes in hearing. The only other published study to assess quality of life in response to medical therapy in NF2 is the work of Morris et al, who demonstrated significant improvements on the NFTI-QOL with bevacizumab (249). This disease-specific tool includes a single question (out of 8 in total) regarding the impact of hearing on daily functioning (graded 0-3), has shown correlation with the SF36, and offers the advantage of being much shorter. The NFTI-QOL may be

170 appropriate for use in children (247) upon further evaluation in the younger age group for whom clinical features differ versus adults. A simplified version of hearing disability tool, the SSQ12 may also be relevant for use in children(268).

Observation of lack of improvement in SSQ responses for hearing disability in Patient 1 contrasted with improvement in other quality of life measures. This highlights the potential benefit of systemic therapy in domains other than hearing for complex NF2 patients in whom multiple intra and extracranial tumours are the norm. SF36 responses indicated improvements in physical functioning and pain. Use of a range of tools in this study provided complementary information, identifying secondary benefits of systemic treatment in this disease which impacts patient functioning in multiple domains.

While the symptoms checklist used here detected changes over time, it may contain redundant items, and covers primarily physical factors with little representation of psychosocial factors (although this could be reflected in the simple LOWS). As such the disease-specific NFTI-QOL could be recommended in preference, as a simpler tool, validated for individuals older than 16 years, showing good correlation with other existing tools which measure physical and psychological factors including the SF36. This tool may also be helpful during routine clinical care to monitor change in patient wellbeing over time outside a clinical trial setting, and has prompted addition of supportive management over time in response to reduction in scores, with subsequent improvement in scores following the intervention (247).

Over the last several years, members of the REiNS International collaboration have considered options and recently produced recommendations for additional patient reported outcomes for pain and physical functioning which should be incorporated into future studies (152). Other outcome measures may be needed in selected individuals over time, relevant to other specific issues, such as visual functioning (likely visual acuity), as evident in Patient 7 in this study. Alignment of outcome measures across sites offers the opportunity for collaboration, and increased power in interpreting treatment responses in this rare condition.

171 Medication Tolerability Bevacizumab was generally well tolerated in our patients. Hypertension and proteinuria are well recognised complications, and of particular concern in this population of predominantly young patients who may require prolonged treatment. Hypertension and proteinuria occurred only in a single patient (14%; patient aged 34 years), in contrast with higher incidence reported in larger cohorts. Interestingly, this individual was treated according to the three-weekly infusion schedule using a higher dose, which has been identified in one report as associated with increased rates of hypertension(287). One of two additional children treated at our centre subsequent to this report required dose adjustment and treatment holidays due to these complications. The low frequency of hypertension and proteinuria in our cohort may reflect the shorter follow up duration, as cumulative medication dose has been found to impact on hypertension in particular(288). Rates as high as 58% for hypertension and 62% for proteinuria have been reported after a median of 12.8 months of medication and almost double for proteinuria among 33 patients (median 28 years; fortnightly dosing 5mg/kg/dose)(288). In contrast, median time to onset of hypertension was shorter at 2.7 months in the UK cohort, with increased incidence of 50% in adults older than 30 years(287). Most common side effects in this group were fatigue, hypertension and infection(287).

Various infections were observed in Australian patients. One patient required hospitalisation during treatment, which may have been treatment related, for CNS infection (complicated by seizure) with gastrointestinal haemorrhage and peripheral thrombotic complications. Bevacizumab was recommenced later without significant adverse effects. Seizure in association with CNS infection has been reported in other patients. Menstrual irregularities occurred in this small group, and appear to be a common experience in other centres as well, with 19% affected in the UK NF2 cohort reported recently(287). Particular care is needed in counselling regarding potential impact on fertility, with appropriate anticipatory care in young women with NF2.

Regarding optimal dosing regimens versus efficacy and side effects, a European centre prescribed adults 10mg/kg on a fortnightly basis for 6 months, followed by 15mg/kg every three weeks, and did not demonstrate further benefit in response.

172 (N=12). Radiologic response (>20% volume reduction) was reported in 39% tumours (7/18 VS), and hearing response in 23% (3/13 ears) using variable outcome measures (not including statistical significance according to published tables for SDS). One fatality occurred secondary to intracerebral haemorrhage, which may have been treatment related. It may be that dose reduction to 2.5mg/kg fortnightly offers sustained benefit with reduced risks in at least a subset of patients, after response is demonstrated on initial higher doses(249, 282).

Response in Children Differential response of children to bevacizumab therapy warrants comment. As the only child in this group, response to treatment was generally poorer in patient 7 compared with other patients, despite commencement on a higher medication dose. In a small French cohort of seven children reported recently (7 patients, 11 VS), over half received 10mg/kg/dose (4/7) while the remainder were treated with 5mg/kg/dose(248) fortnightly. No comment was made regarding dose adjustment during ongoing treatment. Median tumour volumes were smaller and word recognition scores overall indicated better hearing at baseline (1.2 cm3, range 0.52– 13.5; word recognition score 90 %, range 0–100) compared with this dataset, and the predominantly adult UK and USA series. While annual tumour growth rate slowed significantly on treatment (138% versus 36% p=0.043), only a single tumour (14%) showed radiologic response (>20% volume reduction), and a single patient showed statistically significant improvement in word recognition score (248). Morris et al also observed a tendency for ongoing tumour growth in the six children followed in their study(249).

Commencement of therapy in children with smaller tumours likely reflects anticipation of increased severity/morbidity in this group compared with adults. Optimal indications for commencement of therapy should be discussed-at onset of hearing loss or a pre-determined tumor volume or growth rate. Increased dose at initiation of treatment may enhance response. Consideration should be given to the pattern of tumour growth/progression in children versus adults, and whether response criteria in the paediatric age group should be different, ie. stabilization of tumour growth in progressive tumours may be an acceptable endpoint compared with volume reduction in adults. Pooled results for children treated to date, along with inclusion of

173 paediatric patients in clinical trials will help inform this debate. Despite the need to control aggressive disease in children, assessment of response must be carefully balanced against risk of adverse effects of treatment.

Practical challenges Difficulties encountered during this study included securing a supply of medication, which varied across regional health districts, and between private health insurers, raising ethical issues about inequity of access among patients. Interruption to treatment was due to medication supply issues in several cases. Strong advocacy for all individuals meeting eligibility criteria for treatment assisted in acquisition of medication. In addition, coordination between multiple departments to ensure adequate response monitoring required significant clinician input and administrative support, and limited availability of follow up data in some cases.

Conclusion In conclusion, bevacizumab was well tolerated and offered improvements across multiple domains in these Australian patients with NF2 associated tumours. Individual responses varied, with radiologic response of vestibular schwannomas comparable to that reported in studies from other sites. Although methodologic issues limited interpretation of hearing response alongside other populations, improvement was demonstrated in a proportion of cases using secondary outcome measures. Patient reported outcomes including experience of hearing disability and quality of life provided other evidence of benefit from therapy in most cases. Therefore, further consideration must be given to the place of bevacizumab for treatment of NF2 patients beyond change in hearing and tumour volume. In future, incorporating baseline imaging assessments such as apparent diffusion coefficient and contrast transfer coefficient on dynamic contrast-enhanced MRI may assist with patient selection and predicting response to therapy for VS and other schwannomas. Since this study, several additional children have been treated at our site. It is hoped that the place of bevacizumab therapy for paediatric patients will become clearer over time as additional data become available.

174 CHAPTER 9. EFFECT OF BEVACIZUMAB ON TARGET AND NON-TARGET TUMOURS IN A SINGLE PATIENT WITH NEUROFIBROMATOSIS TYPE 2

Introduction

Neurofibromatosis Type 2 (NF2) is an autosomal dominant condition associated with formation of multiple tumours affecting the central and peripheral nervous system in affected individuals, due to mutations in the NF2 tumour suppressor gene on chromosome 22 (167). This includes schwannomas, meningiomas, ependymomas and other glial tumours occurring within both the intracranial and spinal compartments and on peripheral nerves. Whilst histologically benign, the behaviour of NF2 associated tumours is often malignant, causing significant morbidity including seizures, deafness, blindness, pain, paralysis, and early mortality in many cases (167, 200). Symptoms are primarily caused by compression of associated nerves and adjacent structures. As such, tumour mass is an important characteristic, with rapid symptomatic progression possible once a critical, location-dependent threshold is exceeded. Radiologic response to treatment is therefore an important endpoint to monitor in the assessment of novel medications to treat such tumours. Parameters such as change in symptoms, functional assessments and quality of life are other important elements to assess in response evaluations, as reduction in the bulk of asymptomatic tumours may be irrelevant to the patient. Functional assessments are considered in greater detail elsewhere.

Surgical intervention has been the mainstay of treatment until recently (186). Radiosurgery and radiotherapy have a role in selected cases, but a cautious approach to this treatment modality is taken in many centres due to concerns regarding increased risk of secondary tumour formation and malignant transformation in populations with an underlying tumour predisposition (189). Improvements in our understanding of tumour biology and the molecular pathways underpinning this genetic condition have provided a rationale for the development and use of novel medications in clinical trials initially focussing on vestibular schwannomas, the hallmark tumour affecting 95% of patients (225, 231). Guidelines for radiologic trial

175 end points have been proposed for assessing the primary tumour target, vestibular schwannoma (124, 219).

Beneficial effect of bevacizumab (monoclonal antibody against vascular endothelial derived growth factor (VEGF); Avastin, Roche) has been described for vestibular schwannomas in a series of patients as evidenced by an improvement in hearing and decrease in tumour size (37, 227, 228), due to altered vascular supply to tumours. Limited benefit has been observed in treatment of intracranial meningiomas (226, 229). However, despite the co-existence of multiple other intracranial and spinal tumours in most patients, limited information is available regarding treatment effect on tumours other than the primary target lesion, vestibular schwannoma. Shrinkage or stabilisation of growth rate of non-target tumours may also constitute treatment response associated with significant clinical benefit to the patient. In fact, spinal tumours may be the symptomatic, target tumour in some cases. More information is needed about potential response of these tumours to agents such as bevacizumab.

This chapter presents a detailed assessment of radiologic response of vestibular schwannomas and other intracranial and extracranial tumours following 12 months treatment with bevacizumab in a single patient with NF2, to assess the potential utility of this agent for both target and non-target tumours.

Methods

A twenty-three-year-old woman diagnosed with Neurofibromatosis Type 2 was referred to our specialist centre for assessment of multiple NF2 associated tumours in August of 2010. The patient initially presented aged 15 years, with a peripheral schwannoma and unilateral foot drop. The diagnosis of NF2 was made following identification of bilateral vestibular schwannomas at age 17 years, due to a pathogenic mutation in the NF2 gene [c.41_42delTC p.Leu14GInfsX34]. The patient had undergone resection of multiple spinal tumours in a series of three operations over the preceding 6 years.

Referral was prompted by deterioration of hearing, and increasing headaches with

176 vomiting (risk of brain stem compression) due to bilateral vestibular schwannomas. Pure tone audiometry indicated a mild to moderate severe bilateral mixed hearing loss (20bB at 250 Hz dropping to 45dB bilaterally at 1000Hz, varying between 35-55dB up to 2000Hz, dropping from 45 to 80dB bilaterally at higher frequencies). Speech audiometry (AB words) showed 94% correct at 70dB in the right ear, and 91% at 75dB in the left ear. Sensation to light touch was reduced in the distribution of all branches of the trigeminal nerve (V1>V2/V3). The left corneal reflex was absent. Significant muscle wasting and weakness was evident in selected muscle groups. Independent ambulation with a high stepping gait was possible, with reduced balance and coordination (unable to perform tandem gait).

Cranial MRI showed a large left trigeminal schwannoma adjacent to the left vestibular schwannoma exerting additional mass effect (Figure 9.1a). Growth in multiple tumours was evident over time on serial cranial and spinal MRI. Following multidisciplinary review and discussion, the patient was treated with bevacizumab (Avastin, Roche Pharma) at 5mg/kg intravenous infusion on a fortnightly basis. Treatment was well tolerated with no missed doses.

Patient symptoms were assessed during clinical follow up every 3 months using standardised questionnaires, and functional assessments including hearing testing and gait examination. Patient reported outcomes were assessed using the Speech, Spatial and Qualities of Hearing Scale (SSQ) (255) previously used in the evaluation of patients undergoing surgical removal of unilateral vestibular schwannoma (257). Quality of life was assessed using the widely validated SF36 questionnaire which has been reported in evaluation of NF2 patients undergoing surgical removal of unilateral vestibular schwannoma (261). Side effects of treatment were recorded (details presented in Chapter 8).

Radiologic response to treatment was assessed in target tumours causing active disease with significant associated morbidity (bilateral vestibular schwannomas and left trigeminal schwannoma) and non-target tumours (other intracranial, intraspinal and peripheral tumours meeting size criteria) with the potential to cause symptoms and signs with increasing tumour growth.

177

Figure 9.1 Axial T1 fat saturated gadolinium enhanced MRI showing intracranial target lesions pre-treatment (a) and post-treatment (b); Decreased brain stem mass effect and increased cystic change (presumed necrosis) in large left trigeminal schwannoma with stable findings for bilateral vestibular schwannomas (b).

178 MRIs were acquired on a 1.5T Phillips scanner at the Perth Radiological Clinic, Western Australia. Volumes were measured for intracranial tumours measuring >0.5cm in longest diameter and spinal tumours measuring >1.0cm in longest diameter (T0), then at the time of commencement of treatment 9 months later (T1), in the absence of a 12 month interval pre-treatment scan, and after 12 months treatment (T2). Measurements were made in the axial and coronal planes, on gadolinium enhanced T1 weighted sequences. If theT1W GAD series was unavailable, T2 TSE sequence images were used. Volume underestimates are reported for a single tumour due to incomplete coverage of the lesion at time points T1 and T2 (L3/L4 tumour). Three-dimensional tumour volumes were estimated using (3D) slicer software (http://www.slicer.org). This semi-automated method has been validated against manual segmentation approaches (289), used in clinical brain tumour studies (290, 291). Tumours were considered inevaluable if the entire tumour was not fully imaged, or a complete set of images in two planes without gaps was unavailable. Non- evaluable tumours were not included in the final analysis.

Two independent radiologists (JL, LG) reviewed the scans, calculating volumes for all tumours at T0 (baseline), T1 (9 months after T0, commencement of bevacizumab) and T2 (post-treatment, 12 months after initiation of bevacizumab). In any case where volumes differed in excess of 10% between radiologist 1 and 2, tumours were remeasured and a consensus reached regarding optimal measurement. Combined average tumour volumes were then calculated. Baseline growth rates (%) were estimated during the 9-month pre-treatment period (T1-T0/T0), along with growth rates after 12 months treatment (T2-T1/T1), by each reviewer, and then averaged to obtain combined estimates, which are reported here.

Evaluation of inter-rater variability

Independent measurements were available for comparison with our measurements at time points (T1 and T2) for the primary target tumours (bilateral vestibular schwannomas and trigeminal schwannoma) from an established service dedicated to NF tumour volumetric measurement (http://www.nftumormetrics.org). Inter-rater volume differences as a proportion of the smaller estimated tumour volume (to overestimate percentage difference) were calculated for JL and LG at time points T0,

179 T1 and T2 for these three tumours. Equivalent comparisons were made between our combined measurements (averaged volumes from JL and LG) and NFTumormetrics volume measurements for these 3 tumours at T1 and T2. The range and average of variability are reported for comparisons between JL and LG, and our combined data versus NFTumormetrics.

Radiographically significant change in tumour size was conservatively estimated to be greater than 20% change in tumour volume (≥ 20% increase volume=progressive disease; ≥ 20% decrease in volume = treatment effect or baseline tumour regression; 0-20% change in volume = stable disease), as recommended by experts in the field(22, 124, 219). However, on clinical grounds, radiologic treatment response is considered here to include both tumour shrinkage, and stable disease on a background of previous progressive disease (22).

Comment was made on presumed pathology for each lesion based on radiologic appearances and location. Tumours located adjacent to the meninges (with or without enhancement), particularly with appearances of a dural base or tail were presumed meningiomas. Tumours within the spinal compartment were judged to be schwannomas (including transforaminal lesions) or meningiomas (durally based) or ependymomas if intramedullary. Pathology was not available for correlation with radiologic appearances. Due to the potential uncertainty in pathology without tissue, tumours are reported according to location in several cases.

Results

Seven out of nine tumours meeting size criteria were evaluable in the intracranial compartment, as were seven out of eight tumours in the spinal/paraspinal regions. Intracranially, primary target lesions included bilateral VS and left trigeminal schwannoma (Figure 9.1), and non-target lesions - two presumed schwannomas the left and right carotid spaces, another in the right tip Sylvian region, one presumed meningiomas on the left (selected lesions shown in Figure 9.1). In the spinal region, five presumed schwannomas were identified within the spinal canal, two in the cervical region (Figure 9.2, 9.3), two in the upper thoracic region (not shown), and one in the lumbar region (Figure 9.4a).

180

Figure 9.2 Cervical spinal tumours pre-treatment (coronal T1FS cervical spine MRI, a) and post-treatment (non-fat saturated, gadolinium enhanced, b) with bevacizumab. Right sided C1 tumour volume remained in the stable range versus pre-treatment progression (10% volume reduction). Left sided C2/3 tumour showed radiologic response (42% volume reduction).

181

Figure 9.3 Cervical spinal tumour (C2/3) T1 weighted gadolinium enhanced axial and sagittal MRI images pre- treatment (a-b) and showing tumour shrinkage post-treatment (c-d). Trigeminal schwannoma indicated by thin arrow (a).

182

a b c

Figure 9.4 Extracranial lesions (indicated by arrows) on MRI for patient treated with bevacizumab. MRI showing sagittal view L2 spinal tumour (thick black arrow, a); coronal view parapsinal tumours left longissimus (thin white arrow) and psoas (thick white arrow) (b); axial view left longissimus and psoas tumours (c).

183

Figure 9.5 Large right axillary schwannoma shown in coronal MRI. Inevaluable due to inadequate coverage in the second plane.

184 Two clearly visible and readily measurable presumed schwannomas were included in the lumbar paraspinal area (left longissimus muscle and left psoas; Figure 9.4b,c). A large brachial plexus lesion could not be included as tumour coverage was incomplete (Figure 9.5).

Intracranial baseline tumour volumes ranged between 0.43cc3 and 38.73cc3 (x=7.27, SD=13.90, Table 9.1). 5 of 7 tumours measured less than 4cc3. Baseline growth rates varied from 6.63% to 31.75%, with 3 of 7 tumours showing progression over the 9 months preceding treatment (Table 9.1, Figure 9.6).

In the spinal/paraspinal region, volumes were underestimated for the presumed schwannoma at L3/L4 at time points T1 and T2 due to incomplete coverage of the lesion. However, views were adequate to include with this data. Baseline volumes varied between 3.60cc3 to 29.84cc3 (x=8.45, SD=10.03, Table 2). 4 of 7 tumours measured less than 4.5cc3. The two largest lesions were located in the paraspinal region rather than within the spinal canal. Tumour progression pre-treatment was more frequent than for intracranial tumours, observed for 5 of 7 tumours, with four of these growing in excess of 40 percent volume over 9 months, and one of the paraspinal tumours more than doubling in size (Table 9.2, Figure 9.7).

Qualitative changes were clearly evident on neuroimaging post-treatment, including a decrease in the cystic component of the large trigeminal schwanomma with reduced mass effect, and reduction in size of the right vestibular schwannoma and multiple spinal/paraspinal tumours. In the intracranial compartment, significant tumour shrinkage occurred only for the largest trigeminal schwannoma (41.7% volume decrease), although regression of greater than 18% volume was seen in 2 other lesions, approaching a treatment response (including one vestibular schwannoma). One tumour showed progression, another approached criteria for progression and 2 remained stable (Table 2, Figure 6). Treatment response was achieved in 5 of 7 tumours in the spinal/paraspinal region, while the other 2 lesions remained stable compared with pre-treatment progression. Reduction in tumour volume up to 53% was achieved. No tumours showed progressive growth (Table 9.2, Figure 9.7).

185 Inter-rater variation for the 3 primary tumours (bilateral VS and trigeminal schwannoma) ranged between 2.7 to 12.9% (x =6.9%, SD=3.8) for JL-LG, and 0.8 to 12.6% (x =10.2%, SD=9.7) for combined JL/LG-NF Tumormetrics, the greater variance reflecting 6 (JL/LG-NF Tumormetrics) versus 9 comparisons (JL-LG).

Table 9.1 Volumes and growth rates for intracranial tumours at time points T0, T1 and T2* Tumour Tumour Volume (mL) Baseline Growth Treatment Growth Overall Location T0 T1 T2 Rate (% change Rate (% change Response = T1-T0/T0) =T2-T1/T1) ** Right VS 2.84 3.02 2.44 6.63 -19.32 stable stable** No Left VS 1.83 2.05 2.48 11.87 21.20 stable progression No Left 38.73 46.12 26.91 28.61 -41.71 trigeminal progression regression Yes Right carotid 2.36 4.09 3.32 30.96 -18.74 space progression stable*** Yes Left carotid 10.68 13.72 16.11 14.78 17.40 space stable stable No Right tip 0.43 0.64 0.57 31.75 -9.42 Sylvian progression stable Yes Left 3.64 4.48 4.49 9.52 0.23 meningioma stable stable No

* T0=baseline, T1=T0 + 9 months, commencement bevacizumab, T2=T1 + 12 months, on treatment. Interpretation: 0-20% change in volume = stable disease; 20% increase volume = progressive disease; ≥ 20% decrease in volume = tumour regression; negative number indicates tumour shrinkage; ** Response constitutes either tumour regression or stable disease versus previous progression; ***approaching treatment effect; VS= vestibular schwannoma.

186

Figure 9.6 Growth rates of intracranial tumours at baseline (top/green) and with bevacizumab treatment (bottom/blue).

187

Table 9.2 Volumes and growth rates for extracranial tumours at time points T0, T1 and T2* Tumour Tumour Volume (mL) Baseline Growth Treatment Growth Overall Location T0 T1 T2 Rate (% change Rate (% change Response = T1-T0/T0) =T2-T1/T1) ** Right C1 3.60 5.45 4.89 52.6 -10.15 progression stable Yes

Left C2/3 7.06 8.12 4.71 15.08 -42.07 stable regression Yes

Right T1/2 1.49 2.21 1.92 48.29 -13.34 progression stable Yes

Left T1/2 3.59 5.10 3.83 42.26 -24.67 progression regression Yes

Left L3/4 29.84 38.91 30.93 31.40 -20.68 progression regression Yes

Longissimus 12.73 14.25 6.58 11.84 -53.57 stable regression Yes

Psoas 4.35 10.41 6.26 139.32 -39.87 progression regression Yes

*T0=baseline, T1=T0 + 9 months, commencement bevacizumab, T2=T1 + 12 months, on treatment. Interpretation: 0-20% change in volume = stable disease; 20% increase volume = progressive disease; ≥ 20% decrease in volume = tumour regression; negative number indicates tumour shrinkage; ** Response constitutes either tumour regression or stable disease versus previous progression; VS- vestibular schwannoma.

Functional responses Following treatment, hearing stabilised on a background of progressive decline, and the patient reported improvement in symptoms of headache, neck pain, muscle weakness, and balance, with a subjective improvement in global wellbeing. Functional responses are discussed in greater detail elsewhere (Chapters 7/8).

188

Figure 9.7. Growth rates of spinal and paraspinal tumours at baseline (top/green) and with bevacizumab treatment (bottom/blue).

189 Discussion

This detailed study of tumour responses in a single NF2 patient with high tumour burden adds significantly to existing evidence that NF2 associated tumours, schwannomas, in particular, respond to treatment with the VEGF monoclonal antibody, bevacizumab. Whilst both symptomatic/functional and radiographic responses were observed, the focus of this study was on volumetric response. Shrinkage of tumours occurred in both the intracranial and extracranial regions. In fact, radiographic response was most impressive for extracranial tumours, both in terms of number of tumours demonstrating response and magnitude of response. Radiologic together with symptomatic response of extracranial schwannomas to bevacizumab has been observed at a UK centre among patients with NF2, mosaic NF2 and NF2 mutations associated with schwannomatosis (and documented SMARCB1 mutation) (292), and likely noted in other major NF treatment centres, though not published to our knowledge. One study assessed response of spinal ependymomas to bevacizumab in NF2, demonstrating reduction in intratumoural cyst dimensions and spinal cord oedema. Although changes did not meet the pre-defined study criteria for radiologic response, it was anticipated that changes may be associated with clinical benefit in some patients (293).

In this patient, individual tumour responses varied from greater than 50% volume reduction to 37% tumour growth despite treatment. One vestibular schwannoma approached radiographic response (19.3% volume reduction), while the other progressed. So while the target lesion is likely to be vestibular schwannoma for many patients, not all tumours will benefit. Nevertheless, if some VS shrinkage occurs, with improvement or stabilisation of hearing, this will provide a meaningful benefit to the patient. We note a direct relationship between tumour size and hearing function does not always exist particularly for smaller tumours (294). Furthermore, there may be hearing benefits despite minimal radiographic change (228, 231).

Interpretation of the clinical significance of changes in tumour volumes warrants comment. The magnitude of volumetric response per se, is not the most important factor, as tumour reduction in some locations may have no clinical impact. Conversely, modest tumour shrinkage or volume stabilisation may be very important

190 at a critical location-dependent volume associated with clinical symptoms. In our patient, shrinkage of tumours in the upper cervical region is noteworthy, given these lesions carried a high risk of increased morbidity and early mortality, in the event of progressive disease.

Whilst imaging and tumour measurement in the spinal region was less well standardised/optimised here compared with cranial imaging, the radiographic response seen was well in excess of the threshold value in 3 of 7 tumours, at approximately 40 to 53% volume reduction versus a response threshold of >20% tumour shrinkage. For this patient with a background of 3 prior spinal operations for tumour resection, and persistent significant spinal disease, this result is clinically meaningful.

Factors that may contribute to variable responses of different tumours to treatment other than location, include tumour pathology, size and growth rate, and differences in VEGF expression. Due to the limited number of lesions in this single patient, variability between tumours, and lack of pathological data, it was not possible to draw any firm conclusions regarding response of different tumour types. Whilst variable response was evident in presumed schwannomas, response to treatment did not exceed the assigned threshold for either of the 2 presumed intracranial meningiomas included, consistent with other observations of limited benefit for intracranial meningiomas (226).

Tumour size was not clearly associated with radiographic response in this small study. This contrasts with other evidence now available for vestibular schwannomas (20 tumours in 12 patients), which found larger tumours overall more likely to respond to anti-angiogenic therapy(284).

Baseline tumour growth rate was higher in the spinal/paraspinal tumours compared with the intracranial compartment, and may be important. In the largest series reported to date for vestibular schwannomas, patient age and growth rates were found to be inter-correlated predictors of response (59 VS in 52 patients)(249). Greater responses were noted in actively growing tumours, but poorer responses were seen in the cohort <18 years of age, possibly representing more severe disease. The extent to

191 which baseline growth rate can predict tumour response should be considered further in future population-based studies.

Other approaches that may be helpful in predicting treatment response to monoclonal VEGF antibodies include scintigraphy (295) and specific vascular imaging such as dynamic contrast enhanced MRI (37, 228, 296), for which predictive value has now been confirmed for VS (284). These were not performed here, but may have a role in future trials with bevacizumab and similar agents.

Inconsistencies between scans (available sequences) at different time points (T1 and T2), particularly for spinal MRI is acknowledged as one of the limitations of this study. This demonstrates the benefits of scanning complex NF2 patients at central facilities where protocols are optimised and consistency is maintained over time to reduce tumour measurement error. Imaging recommendations for the primary target tumours (including vestibular schwannomas in NF2) are now available for use in NF clinical trials (124). Given the rarity of NF2, ideally most patients requiring medical treatment should be included in a clinical trial. For clinical surveillance alone, simplified protocols may be appropriate. Consensus recommendations for optimal spinal imaging and approaches to tumour measurement in NF2 would be helpful.

The semi-automated 3D slicer method utilised here yielded volumetric results comparable with those reported by an experienced NF imaging centre. Software is freely available (http://www.slicer.org) and may be useful at other centres performing detailed neuroimaging studies, particularly if unable to submit images to nominated radiology facilities as part of an international trial.

Unfortunately, the effect of treatment on a large brachial plexus tumour could not be evaluated in our patient because it was out of the field of view. Our observations regarding extracranial tumours in this patient, and comparable observations of others, support the potential utility of whole body MRI to measure whole body tumour burden in disease surveillance, and in the evaluation of treatment response in complex NF2 patients (124, 126).

192 Conclusion

This study highlights the fact that multiple intracranial and extracranial tumours show radiologic response to medical therapy for NF2 patients, with associated clinical benefits. Evaluation of novel medications in future clinical trials should incorporate use of vascular biomarkers, and measurement of primary and secondary target tumours using robust radiologic criteria and clinically relevant functional outcomes, on a case by case basis. Medication combinations are likely to be needed, along with multimodal treatment during an individual’s lifetime. As such, the treatment of patients with this rare condition constitutes personalised medicine. The combined experience of individuals through international clinical trial participation, offers the best opportunity to establish optimal treatment regimens over time.

Alongside existing evidence, this report presents an increasingly strong argument in support of the use of medical therapy, including VEGF monoclonal antibodies, for treatment of NF2 associated tumours. Clear radiographic response has been illustrated which, in association with functional improvement, can significantly limit the morbidity caused by this condition, and improve quality of life for individuals and families.

193 CHAPTER 10. OVERVIEW AND FUTURE DIRECTIONS

Despite the clear differences between NF1 and NF2 as distinct tumour suppressor syndromes, a number of similarities exist for these two single gene disorders in the current era of evolving disease-specific approaches to treatment. The development of focal neurological deficits secondary to compression by the tumour impinging on one or multiple nerves is common in both, along with the need to monitor clinical and radiological change over time. Medical treatment options include agents targeting various shared aspects of tumour biology and molecular signalling pathways. In both conditions, translation of novel treatments from the laboratory and animal models to the bedside remains a priority.

At the dawn of molecularly targeted medical therapy for NF1 and NF2, the rationale for treatment and results of initial treatment trials in Australia have been described here using imatinib for plexiform neurofibromas and bevacizumab for vestibular schwannomas. Emphasis has been placed on objective outcome measures and clinically relevant functional parameters, as well as a focus on the patient experience via inclusion of patient reported outcomes.

Although the efficacy of imatinib and bevacizumab was variable, lessons have been learnt which will enhance the clinical care of patients, improve neuroimaging surveillance (providing essential natural history and pre-treatment baseline data for subsequent trials), and the methodology of response evaluation for novel treatments.

It is anticipated that refinements in the application of optimal image acquisition and interpretation according to consensus recommendations (using volumetric tumour measurements of on MRI), will allow confident assessment of change over time for individual patients, and ensure standardisation between centres participating in collaborative studies, as well as comparisons between independent research results (124). Whole-body MRI and MRI-PET may have a role, with recommendations for these techniques still in development (297).

194 Regarding current and future directions at our centre for plexiform neurofibromas in NF1 an emphasis has been placed on identifying children at risk of significant complications early, with a view to prevention of severe manifestations such as those seen in the older adolescents treated in this study. Progressive tumours occurring around the head and neck (including the airway and orbit), the major nerve plexuses and spine, should be included as targets in ongoing and future treatment trials. The goal will be to arrest tumour growth in small tumours early, and to prevent establishment of large fibrotic lesions which may impact adjacent systems (such as bony involvement with scoliosis adjacent to spinal neurofibromas) and be resistant to therapy. Identifying agents that are tolerable and safe in early childhood is essential.

In NF1, recent results with MEK inhibitors for plexiform neurofibromas are encouraging (70). However, more information is needed including possible adverse effects in the short and long term, the optimal time to commence treatment, and duration of therapy. There may be a critical period that is optimal for treatment response. Will this vary with tumour location, rate of growth, or patient genotype? Should the spinal neurofibromatosis phenotype be considered separately? What tumour surveillance will be appropriate for treated lesions in future? Will treatment of plexiform neurofibromas alter the natural history of development of malignant peripheral nerve sheath tumours (MPNST), which arise in pre-existing plexiform neurofibromas in 8-13% of patients, and are a significant cause for early mortality on NF1(88)?

And what of current and future directions in NF2? Fortunately, results to date have established a clear role for angiogenesis inhibition in the treatment of vestibular schwannomas in adults(21). However, the optimal indications for treatment, including when to commence therapy, remain unclear. For example, what is the place of surgical resection versus medical therapy for small tumours in light of results with bevacizumab? Should surgery be deferred in all cases where medication can be offered? Should angiogenesis inhibitors be commenced when tumours exceed set dimensions, or be reserved until functional decline occurs (in one or both ears?), to minimize cost and risk of side effects? Guidelines based on current and evolving data may be helpful, particularly for centres with less experience in the use of angiogenesis inhibitors. However, it is probable that treatment decisions will vary between sites

195 based on a number of variables including differing experience and expertise of the treating multidisciplinary team, and regulations surrounding prescription, cost and availability of medication.

More information is needed regarding the role of angiogenesis inhibitors in treatment of NF2 in childhood. Although benefit has been observed in a small number of children(248), we and others have noted the response to be less impressive for vestibular schwannomas in paediatric patients compared with adults(249). Will this be borne out in extended studies? Does the increased prevalence of symptomatic schwannomas on cranial nerves other than the vestibular nerve, and on other peripheral nerves, impact on response and response evaluation? Alternative indications for treatment (possibly broader than growth and symptoms of vestibular schwannomas) may be more appropriate for children. In addition, it may be important to track radiologic response in a group of tumours over time, along with clinical effects.

There are a number of ongoing clinical trials for NF1 and NF2-associated tumours, and results will determine future directions (21, 24, 298). In the longer term, treatment protocols utilizing multiple medications in parallel or in series may be tolerable and return added benefits (299). It is expected that individualised management will remain the norm, incorporating a multimodal approach including surgery for many patients, and in selected cases, radiosurgery/radiotherapy and other treatments may have a role.

Since design of the treatment trials described here, significant progress has been made in advancing clinical trials in the neurofibromatoses through efforts of the international multidisciplinary Response Evaluation in Neurofibromatosis and Schwannomatosis (REiNS) International Collaboration (25), and the Neurofibromatosis Clinical Trials Consortium (NFCTC) (24), with a view to assessing promising candidate medications most effectively. Recommendations from the REiNS consortium have been helpful for optimizing trial methodology including tumour measurement (124) and functional outcomes pertaining to vision (300), hearing and facial nerve function (214), sleep and pulmonary functioning (151), along with patient reported outcomes for assessing pain and physical functioning (152).

196 Further refinements are ongoing and will offer the tools needed to explore the questions yet to be answered.

Another topic addressed by REiNS for development in future studies involves that of biomarkers to monitor disease, stratify risk of complications and for response stratification (301). Published data on potential biomarkers are available exclusively for NF1 to date, and in the research and development stages only. Nevertheless, biobanking is underway, and recommendations have recently been made regarding protocols for standardised sample collection and storage, minimal clinical datasets and data management. Sites such as The Children’s Hospital at Westmead are well placed to participate in these efforts through contribution of tissue samples along with clinical data. The existing Children’s Hospital at Westmead tumour bank includes 70 samples from individuals with NF1 and NF2, to which more can be readily added per protocol over time (301). To what extent biomarkers from selected tumours can be used to inform observations about whole body disease, ie. response to medication at distant sites, remains to be seen.

In terms of ongoing expert service provision for patients with NF in Australia, the studies described in this thesis have facilitated consolidation of a network of skilled physicians including oncologists, neurologists, radiologists, clinical geneticists and surgical colleagues, in NSW along with out-of-state providers. In the course of this study, advocacy for NF1 and NF2 patients has brought this patient group to the attention of regional hospital drug committees, private health care providers, the national Pharmaceutical Benefits Advisory Committee and the pharmaceutical industry for consideration. The ethical issues around development of disease-specific therapy in rare diseases, including equitable access to expensive drugs without undue delay, have been aired in medical forums for consideration in the broader community. Cost effectiveness evaluations need to be considered, and should include due recognition of the reduced quality of life and loss of income for patients with NF1 and NF2 and their families, which may be relieved by a period of medical therapy.

Regarding routine clinical care at our site, opportunities for enhancement lie in expanding expertise within the clinical team (nursing/psychological support), considering benefits of more comprehensive genetic testing, and issues around

197 medication supply at time of transition. We are fortunate to have a team of experienced and cooperative medical and surgical clinicians dedicated to addressing the needs of the NF population in our region. Patients with complicated NF1 and NF2 experience significant medical and psychosocial morbidity(155, 264); thus comprehensive coordinated specialist services should include dedicated nursing and social/psychological support throughout the lifespan. Such a disease-specific coordinated care approach has been identified as a priority, and demonstrated to improve survival (180, 302). Future endeavours must monitor healthcare goals not only of improved duration, but quality of life.

In the past, genetic testing has not been performed in all cases, as it was not required to confirm the diagnosis. However, over the years, increasing information recommends genotype as a biomarker to inform prognosis and anticipatory care (130, 303) in both NF1 and NF2. It may also be important to assess correlations between genotype/other biomarkers and response to novel medical therapies (284). As such, we plan to offer genetic testing to an increasing proportion of our patients.

As clinical practice changes to encompass medical treatment in a larger number of patients, the issue of medication access at transition to adult services will increasingly arise, for which consultation and planning between paediatric and adult arms of the healthcare system will be necessary.

In conclusion, collaborative efforts and involvement in multi-center clinical research studies where possible, offer the potential for improving the care of Australian patients, as well as facilitating research through enhancement of recruitment and participation. While the challenges presented by the neurofibromatoses remain daunting at times, we are in the strongest position ever to meet them head on with confidence and optimism. The therapeutic landscape is expected to continue evolving in the coming years - a necessary and exciting prospect indeed.

198 References

1. Anderson JL, Gutmann DH. Neurofibromatosis type 1. Handbook of clinical neurology. 2015;132:75-86. 2. Jett K, Friedman JM. Clinical and genetic aspects of neurofibromatosis 1. Genetics in medicine : official journal of the American College of Medical Genetics. 2010;12(1):1-11. 3. Ferner RE, Gutmann DH. Neurofibromatosis type 1 (NF1): diagnosis and management. Handbook of clinical neurology. 2013;115:939-55. 4. Evans DG. Neurofibromatosis type 2. Handbook of clinical neurology. 2015;132:87-96. 5. McClatchey AI. Neurofibromatosis. Annu Rev Pathol. 2007;2:191-216. 6. Hilton DA, Hanemann CO. Schwannomas and their pathogenesis. Brain Pathol. 2014;24(3):205-20. 7. Kresak JL, Walsh M. Neurofibromatosis: A Review of NF1, NF2, and Schwannomatosis. Journal of pediatric genetics. 2016;5(2):98-104. 8. Lin AL, Gutmann DH. Advances in the treatment of neurofibromatosis-associated tumours. Nature reviews Clinical oncology. 2013;10(11):616-24. 9. Ferner RE. Neurofibromatosis 1 and neurofibromatosis 2: a twenty first century perspective. The Lancet Neurology. 2007;6(4):340-51. 10. Evans DG, Birch JM, Ramsden RT. Paediatric presentation of type 2 neurofibromatosis. Archives of disease in childhood. 1999;81(6):496-9. 11. Neurofibromatosis. Conference statement. National Institutes of Health Consensus Development Conference. Archives of neurology. 1988;45(5):575-8. 12. Wallace MR, Marchuk DA, Andersen LB, Letcher R, Odeh HM, Saulino AM, et al. Type 1 neurofibromatosis gene: identification of a large transcript disrupted in three NF1 patients. Science. 1990;249(4965):181-6. 13. Upadhyaya M, Cheryson A, Broadhead W, Fryer A, Shaw DJ, Huson S, et al. A 90 kb DNA deletion associated with neurofibromatosis type 1. Journal of medical genetics. 1990;27(12):738-41. 14. Rouleau GA, Merel P, Lutchman M, Sanson M, Zucman J, Marineau C, et al. Alteration in a new gene encoding a putative membrane-organizing protein causes neuro-fibromatosis type 2. Nature. 1993;363(6429):515-21. 15. Trofatter JA, MacCollin MM, Rutter JL, Murrell JR, Duyao MP, Parry DM, et al. A novel moesin-, ezrin-, radixin-like gene is a candidate for the neurofibromatosis 2 tumor suppressor. Cell. 1993;75(4):826. 16. Gutmann DH, Collins FS. The neurofibromatosis type 1 gene and its protein product, neurofibromin. Neuron. 1993;10(3):335-43. 17. MacCollin M, Mohney T, Trofatter J, Wertelecki W, Ramesh V, Gusella J. DNA diagnosis of neurofibromatosis 2. Altered coding sequence of the merlin tumor suppressor in an extended pedigree. Jama. 1993;270(19):2316-20. 18. Kehrer-Sawatzki H, Farschtschi S, Mautner VF, Cooper DN. The molecular pathogenesis of schwannomatosis, a paradigm for the co-involvement of multiple tumour suppressor genes in tumorigenesis. Human genetics. 2017;136(2):129-48. 19. MacCollin M, Chiocca EA, Evans DG, Friedman JM, Horvitz R, Jaramillo D, et al. Diagnostic criteria for schwannomatosis. Neurology. 2005;64(11):1838-45. 20. Plotkin SR, Blakeley JO, Evans DG, Hanemann CO, Hulsebos TJ, Hunter-Schaedle K, et al. Update from the 2011 International Schwannomatosis Workshop: From genetics to diagnostic criteria. American journal of medical genetics Part A. 2013;161A(3):405-16. 21. Karajannis MA, Ferner RE. Neurofibromatosis-related tumors: emerging biology and therapies. Current opinion in pediatrics. 2015;27(1):26-33. 22. Plotkin SR, Halpin C, Blakeley JO, Slattery WH, 3rd, Welling DB, Chang SM, et al. Suggested response criteria for phase II antitumor drug studies for neurofibromatosis type 2 related vestibular schwannoma. Journal of neuro-oncology. 2009;93(1):61-77. 23. Evans DG, Kalamarides M, Hunter-Schaedle K, Blakeley J, Allen J, Babovic-Vuskanovic D, et al. Consensus recommendations to accelerate clinical trials for neurofibromatosis type 2. Clinical cancer research : an official journal of the American Association for Cancer Research. 2009;15(16):5032-9. 24. Gutmann DH, Blakeley JO, Korf BR, Packer RJ. Optimizing biologically targeted clinical trials for neurofibromatosis. Expert Opin Investig Drugs. 2013;22(4):443-62.

199 25. Plotkin SR, Blakeley JO, Dombi E, Fisher MJ, Hanemann CO, Walsh KS, et al. Achieving consensus for clinical trials: the REiNS International Collaboration. Neurology. 2013;81(21 Suppl 1):S1-5. 26. Packer RJ, Gutmann DH, Rubenstein A, Viskochil D, Zimmerman RA, Vezina G, et al. Plexiform neurofibromas in NF1: toward biologic-based therapy. Neurology. 2002;58(10):1461- 70. 27. Packer RJ, Rosser T. Therapy for plexiform neurofibromas in children with neurofibromatosis 1: an overview. J Child Neurol. 2002;17(8):638-41; discussion 46-51. 28. Dombi E, Solomon J, Gillespie AJ, Fox E, Balis FM, Patronas N, et al. NF1 plexiform neurofibroma growth rate by volumetric MRI: relationship to age and body weight. Neurology. 2007;68(9):643-7. 29. Babovic-Vuksanovic D, Ballman K, Michels V, McGrann P, Lindor N, King B, et al. Phase II trial of pirfenidone in adults with neurofibromatosis type 1. Neurology. 2006;67(10):1860-2. 30. Widemann BC, Salzer WL, Arceci RJ, Blaney SM, Fox E, End D, et al. Phase I trial and pharmacokinetic study of the farnesyltransferase inhibitor tipifarnib in children with refractory solid tumors or neurofibromatosis type I and plexiform neurofibromas. Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 2006;24(3):507-16. 31. Weiss B, Widemann BC, Wolters P, Dombi E, Vinks AA, Cantor A, et al. Sirolimus for non- progressive NF1-associated plexiform neurofibromas: an NF clinical trials consortium phase II study. Pediatric blood & cancer. 2014;61(6):982-6. 32. Gupta A, Cohen BH, Ruggieri P, Packer RJ, Phillips PC. Phase I study of thalidomide for the treatment of plexiform neurofibroma in neurofibromatosis 1. Neurology. 2003;60(1):130-2. 33. Champagne MA, Fu CH, Chang M, Chen H, Gerbing RB, Alonzo TA, et al. Higher dose imatinib for children with de novo chronic phase chronic myelogenous leukemia: a report from the Children's Oncology Group. Pediatric blood & cancer. 2011;57(1):56-62. 34. Plotkin SR, Halpin C, McKenna MJ, Loeffler JS, Batchelor TT, Barker FG, 2nd. Erlotinib for progressive vestibular schwannoma in neurofibromatosis 2 patients. Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 2010;31(7):1135-43. 35. Plotkin SR, Singh MA, O'Donnell CC, Harris GJ, McClatchey AI, Halpin C. Audiologic and radiographic response of NF2-related vestibular schwannoma to erlotinib therapy. Nature clinical practice Oncology. 2008;5(8):487-91. 36. Karajannis MA, Legault G, Hagiwara M, Ballas MS, Brown K, Nusbaum AO, et al. Phase II trial of lapatinib in adult and pediatric patients with neurofibromatosis type 2 and progressive vestibular schwannomas. Neuro-oncology. 2012;14(9):1163-70. 37. Plotkin SR, Stemmer-Rachamimov AO, Barker FG, 2nd, Halpin C, Padera TP, Tyrrell A, et al. Hearing improvement after bevacizumab in patients with neurofibromatosis type 2. The New England journal of medicine. 2009;361(4):358-67. 38. Cichowski K, Jacks T. NF1 tumor suppressor gene function: narrowing the GAP. Cell. 2001;104(4):593-604. 39. Shilyansky C, Karlsgodt KH, Cummings DM, Sidiropoulou K, Hardt M, James AS, et al. Neurofibromin regulates corticostriatal inhibitory networks during working memory performance. Proceedings of the National Academy of Sciences of the United States of America. 2010;107(29):13141-6. 40. Ferner RE. The neurofibromatoses. Practical neurology. 2010;10(2):82-93. 41. Evans DG, Baser ME, McGaughran J, Sharif S, Howard E, Moran A. Malignant peripheral nerve sheath tumours in neurofibromatosis 1. Journal of medical genetics. 2002;39(5):311-4. 42. Friedrich RE, Hartmann M, Mautner VF. Malignant peripheral nerve sheath tumors (MPNST) in NF1-affected children. Anticancer research. 2007;27(4A):1957-60. 43. Evans DG, O'Hara C, Wilding A, Ingham SL, Howard E, Dawson J, et al. Mortality in neurofibromatosis 1: in North West England: an assessment of actuarial survival in a region of the UK since 1989. European journal of human genetics : EJHG. 2011;19(11):1187-91. 44. Varan A, Sen H, Aydin B, Yalcin B, Kutluk T, Akyuz C. Neurofibromatosis type 1 and malignancy in childhood. Clinical genetics. 2016;89(3):341-5. 45. Williams VC, Lucas J, Babcock MA, Gutmann DH, Korf B, Maria BL. Neurofibromatosis type 1 revisited. Pediatrics. 2009;123(1):124-33. 46. Ferner RE, Huson SM, Thomas N, Moss C, Willshaw H, Evans DG, et al. Guidelines for the diagnosis and management of individuals with neurofibromatosis 1. Journal of medical genetics. 2007;44(2):81-8.

200 47. Messiaen LM, Callens T, Mortier G, Beysen D, Vandenbroucke I, Van Roy N, et al. Exhaustive mutation analysis of the NF1 gene allows identification of 95% of mutations and reveals a high frequency of unusual splicing defects. Human mutation. 2000;15(6):541-55. 48. Mautner VF, Kluwe L, Friedrich RE, Roehl AC, Bammert S, Hogel J, et al. Clinical characterisation of 29 neurofibromatosis type-1 patients with molecularly ascertained 1.4 Mb type-1 NF1 deletions. Journal of medical genetics. 2010;47(9):623-30. 49. Upadhyaya M, Huson SM, Davies M, Thomas N, Chuzhanova N, Giovannini S, et al. An absence of cutaneous neurofibromas associated with a 3-bp inframe deletion in exon 17 of the NF1 gene (c.2970-2972 delAAT): evidence of a clinically significant NF1 genotype-phenotype correlation. American journal of human genetics. 2007;80(1):140-51. 50. Rojnueangnit K, Xie J, Gomes A, Sharp A, Callens T, Chen Y, et al. High Incidence of Noonan Syndrome Features Including Short Stature and Pulmonic Stenosis in Patients carrying NF1 Missense Mutations Affecting p.Arg1809: Genotype-Phenotype Correlation. Human mutation. 2015;36(11):1052-63. 51. Evans DG, Wallace A. An update on age related mosaic and offspring risk in neurofibromatosis 2 (NF2). Journal of medical genetics. 2009;46(11):792. 52. Messiaen L, Yao S, Brems H, Callens T, Sathienkijkanchai A, Denayer E, et al. Clinical and mutational spectrum of neurofibromatosis type 1-like syndrome. Jama. 2009;302(19):2111-8. 53. Hyman SL, Shores A, North KN. The nature and frequency of cognitive deficits in children with neurofibromatosis type 1. Neurology. 2005;65(7):1037-44. 54. Mautner VF, Kluwe L, Thakker SD, Leark RA. Treatment of ADHD in neurofibromatosis type 1. Developmental medicine and child neurology. 2002;44(3):164-70. 55. Payne JM, Moharir MD, Webster R, North KN. Brain structure and function in neurofibromatosis type 1: current concepts and future directions. Journal of neurology, neurosurgery, and psychiatry. 2010;81(3):304-9. 56. Dilts CV, Carey JC, Kircher JC, Hoffman RO, Creel D, Ward K, et al. Children and adolescents with neurofibromatosis 1: a behavioral phenotype. J Dev Behav Pediatr. 1996;17(4):229-39. 57. Thompson HL, Viskochil DH, Stevenson DA, Chapman KL. Speech-language characteristics of children with neurofibromatosis type 1. American journal of medical genetics Part A. 2010;152A(2):284-90. 58. Li W, Cui Y, Kushner SA, Brown RA, Jentsch JD, Frankland PW, et al. The HMG-CoA reductase inhibitor lovastatin reverses the learning and attention deficits in a mouse model of neurofibromatosis type 1. Curr Biol. 2005;15(21):1961-7. 59. Payne JM, Barton B, Ullrich NJ, Cantor A, Hearps SJ, Cutter G, et al. Randomized placebo- controlled study of lovastatin in children with neurofibromatosis type 1. Neurology. 2016;87(24):2575-84. 60. Listernick R, Ferner RE, Liu GT, Gutmann DH. Optic pathway gliomas in neurofibromatosis-1: controversies and recommendations. Annals of neurology. 2007;61(3):189-98. 61. Thiagalingam S, Flaherty M, Billson F, North K. Neurofibromatosis type 1 and optic pathway gliomas: follow-up of 54 patients. Ophthalmology. 2004;111(3):568-77. 62. Chang L, El-Dairi MA, Frempong TA, Burner EL, Bhatti MT, Young TL, et al. Optical coherence tomography in the evaluation of neurofibromatosis type-1 subjects with optic pathway gliomas. Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus / American Association for Pediatric Ophthalmology and Strabismus. 2010;14(6):511-7. 63. Fisher MJ, Loguidice M, Gutmann DH, Listernick R, Ferner RE, Ullrich NJ, et al. Visual outcomes in children with neurofibromatosis type 1-associated optic pathway glioma following chemotherapy: a multicenter retrospective analysis. Neuro-oncology. 2012;14(6):790-7. 64. Rosser T, Packer RJ. Intracranial neoplasms in children with neurofibromatosis 1. J Child Neurol. 2002;17(8):630-7; discussion 46-51. 65. Korf BR. Plexiform neurofibromas. American journal of medical genetics. 1999;89(1):31-7. 66. Nguyen R, Kluwe L, Fuensterer C, Kentsch M, Friedrich RE, Mautner VF. Plexiform neurofibromas in children with neurofibromatosis type 1: frequency and associated clinical deficits. The Journal of pediatrics. 2011;159(4):652-5 e2. 67. Wolters PL, Burns KM, Martin S, Baldwin A, Dombi E, Toledo-Tamula MA, et al. Pain interference in youth with neurofibromatosis type 1 and plexiform neurofibromas and relation to disease severity, social-emotional functioning, and quality of life. American journal of medical genetics Part A. 2015;167A(9):2103-13.

201 68. Robertson KA, Nalepa G, Yang FC, Bowers DC, Ho CY, Hutchins GD, et al. Imatinib mesylate for plexiform neurofibromas in patients with neurofibromatosis type 1: a phase 2 trial. The Lancet Oncology. 2012;13(12):1218-24. 69. Weiss B, Widemann BC, Wolters P, Dombi E, Vinks A, Cantor A, et al. Sirolimus for progressive neurofibromatosis type 1-associated plexiform neurofibromas: a neurofibromatosis Clinical Trials Consortium phase II study. Neuro-oncology. 2015;17(4):596-603. 70. Dombi E, Baldwin A, Marcus LJ, Fisher MJ, Weiss B, Kim A, et al. Activity of Selumetinib in Neurofibromatosis Type 1-Related Plexiform Neurofibromas. The New England journal of medicine. 2016;375(26):2550-60. 71. Bates JE, Peterson CR, Dhakal S, Giampoli EJ, Constine LS. Malignant peripheral nerve sheath tumors (MPNST): a SEER analysis of incidence across the age spectrum and therapeutic interventions in the pediatric population. Pediatric blood & cancer. 2014;61(11):1955-60. 72. Mautner VF, Friedrich RE, von Deimling A, Hagel C, Korf B, Knofel MT, et al. Malignant peripheral nerve sheath tumours in neurofibromatosis type 1: MRI supports the diagnosis of malignant plexiform neurofibroma. Neuroradiology. 2003;45(9):618-25. 73. Moharir M, London K, Howman-Giles R, North K. Utility of positron emission tomography for tumour surveillance in children with neurofibromatosis type 1. European journal of nuclear medicine and molecular imaging. 2010;37(7):1309-17. 74. Fisher MJ. The Use of PET in the Evaluation of Tumors in Children with Neurofibromatosis Type 1. PET Clin. 2008;3(4):531-49. 75. Zehou O, Fabre E, Zelek L, Sbidian E, Ortonne N, Banu E, et al. Chemotherapy for the treatment of malignant peripheral nerve sheath tumors in neurofibromatosis 1: a 10-year institutional review. Orphanet journal of rare diseases. 2013;8:127. 76. Cairns AG, North KN. Cerebrovascular dysplasia in neurofibromatosis type 1. Journal of neurology, neurosurgery, and psychiatry. 2008;79(10):1165-70. 77. Ostendorf AP, Gutmann DH, Weisenberg JL. Epilepsy in individuals with neurofibromatosis type 1. Epilepsia. 2013;54(10):1810-4. 78. Balestri P, Vivarelli R, Grosso S, Santori L, Farnetani MA, Galluzzi P, et al. Malformations of cortical development in neurofibromatosis type 1. Neurology. 2003;61(12):1799-801. 79. Gales J, Prayson RA. Hippocampal sclerosis and associated focal cortical dysplasia-related epilepsy in neurofibromatosis type I. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia. 2016. 80. Vivarelli R, Grosso S, Calabrese F, Farnetani M, Di Bartolo R, Morgese G, et al. Epilepsy in neurofibromatosis 1. J Child Neurol. 2003;18(5):338-42. 81. Ruggieri M, Iannetti P, Clementi M, Polizzi A, Incorpora G, Spalice A, et al. Neurofibromatosis type 1 and infantile spasms. Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery. 2009;25(2):211-6. 82. Afridi SK, Leschziner GD, Ferner RE. Prevalence and clinical presentation of headache in a National Neurofibromatosis 1 Service and impact on quality of life. American journal of medical genetics Part A. 2015;167A(10):2282-5. 83. Delucia TA, Yohay K, Widmann RF. Orthopaedic aspects of neurofibromatosis: update. Current opinion in pediatrics. 2011;23(1):46-52. 84. Schindeler A, Birke O, Yu NY, Morse A, Ruys A, Baldock PA, et al. Distal tibial fracture repair in a neurofibromatosis type 1-deficient mouse treated with recombinant bone morphogenetic protein and a bisphosphonate. J Bone Joint Surg Br. 2011;93(8):1134-9. 85. Heerva E, Leinonen P, Kuorilehto T, Peltonen S, Poyhonen M, Vaananen K, et al. Neurofibromatosis 1-related osteopenia often progresses to osteoporosis in 12 years. Calcif Tissue Int. 2013;92(1):23-7. 86. Heerva E, Huilaja L, Leinonen P, Peltonen S, Peltonen J. Follow-up of six patients with neurofibromatosis 1-related osteoporosis treated with alendronate for 23 months. Calcif Tissue Int. 2014;94(6):608-12. 87. Binning MJ, Liu JK, Kestle JR, Brockmeyer DL, Walker ML. Optic pathway gliomas: a review. Neurosurgical focus. 2007;23(5):E2. 88. Ferner RE, Gutmann DH. International consensus statement on malignant peripheral nerve sheath tumors in neurofibromatosis. Cancer research. 2002;62(5):1573-7. 89. Katz D, Lazar A, Lev D. Malignant peripheral nerve sheath tumour (MPNST): the clinical implications of cellular signalling pathways. Expert reviews in molecular medicine. 2009;11:e30. 90. Koptan W, ElMiligui Y. Surgical correction of severe dystrophic neurofibromatosis scoliosis: an experience of 32 cases. European spine journal : official publication of the European Spine

202 Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2010;19(9):1569-75. 91. Baaj AA, Agazzi S, Sayed ZA, Toledo M, Spetzler RF, van Loveren H. Surgical management of moyamoya disease: a review. Neurosurgical focus. 2009;26(4):E7. 92. Grill J, Couanet D, Cappelli C, Habrand JL, Rodriguez D, Sainte-Rose C, et al. Radiation- induced cerebral vasculopathy in children with neurofibromatosis and optic pathway glioma. Annals of neurology. 1999;45(3):393-6. 93. Merchant TE, Kun LE, Wu S, Xiong X, Sanford RA, Boop FA. Phase II trial of conformal radiation therapy for pediatric low-grade glioma. Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 2009;27(22):3598-604. 94. Krab LC, de Goede-Bolder A, Aarsen FK, Pluijm SM, Bouman MJ, van der Geest JN, et al. Effect of simvastatin on cognitive functioning in children with neurofibromatosis type 1: a randomized controlled trial. Jama. 2008;300(3):287-94. 95. Brossier NM, Gutmann DH. Improving outcomes for neurofibromatosis 1-associated brain tumors. Expert review of anticancer therapy. 2015;15(4):415-23. 96. Kim A, Gillespie A, Dombi E, Goodwin A, Goodspeed W, Fox E, et al. Characteristics of children enrolled in treatment trials for NF1-related plexiform neurofibromas. Neurology. 2009;73(16):1273-9. 97. Widemann BC, Babovic-Vuksanovic D, Dombi E, Wolters PL, Goldman S, Martin S, et al. Phase II trial of pirfenidone in children and young adults with neurofibromatosis type 1 and progressive plexiform neurofibromas. Pediatric blood & cancer. 2014;61(9):1598-602. 98. Widemann BC, Dombi E, Gillespie A, Wolters PL, Belasco J, Goldman S, et al. Phase 2 randomized, flexible crossover, double-blinded, placebo-controlled trial of the farnesyltransferase inhibitor tipifarnib in children and young adults with neurofibromatosis type 1 and progressive plexiform neurofibromas. Neuro-oncology. 2014;16(5):707-18. 99. Jakacki RI, Dombi E, Steinberg SM, Goldman S, Kieran MW, Ullrich NJ, et al. Phase II trial of pegylated interferon alfa-2b in young patients with neurofibromatosis type 1 and unresectable plexiform neurofibromas. Neuro-oncology. 2016. 100. Kissil JL, Blakeley JO, Ferner RE, Huson SM, Kalamarides M, Mautner VF, et al. What's new in neurofibromatosis? Proceedings from the 2009 NF Conference: new frontiers. American journal of medical genetics Part A. 2010;152A(2):269-83. 101. Huson SM, Acosta MT, Belzberg AJ, Bernards A, Chernoff J, Cichowski K, et al. Back to the future: proceedings from the 2010 NF Conference. American journal of medical genetics Part A. 2011;155A(2):307-21. 102. Ullrich NJ, Zimmerman M, Smith E, Irons M, Marcus K, Kieran MW. Association of rapidly progressive moyamoya syndrome with bevacizumab treatment for glioblastoma in a child with neurofibromatosis type 1. J Child Neurol. 2011;26(2):228-30. 103. Ardern-Holmes SL, North KN. Therapeutics for childhood neurofibromatosis type 1 and type 2. Current treatment options in neurology. 2011;13(6):529-43. 104. Prada CE, Rangwala FA, Martin LJ, Lovell AM, Saal HM, Schorry EK, et al. Pediatric plexiform neurofibromas: impact on morbidity and mortality in neurofibromatosis type 1. The Journal of pediatrics. 2012;160(3):461-7. 105. Waggoner DJ, Towbin J, Gottesman G, Gutmann DH. Clinic-based study of plexiform neurofibromas in neurofibromatosis 1. American journal of medical genetics. 2000;92(2):132-5. 106. Huson SM, Harper PS, Compston DA. Von Recklinghausen neurofibromatosis. A clinical and population study in south-east Wales. Brain : a journal of neurology. 1988;111 ( Pt 6):1355-81. 107. Nguyen R, Dombi E, Widemann BC, Solomon J, Fuensterer C, Kluwe L, et al. Growth dynamics of plexiform neurofibromas: a retrospective cohort study of 201 patients with neurofibromatosis 1. Orphanet journal of rare diseases. 2012;7:75. 108. Mautner VF, Asuagbor FA, Dombi E, Funsterer C, Kluwe L, Wenzel R, et al. Assessment of benign tumor burden by whole-body MRI in patients with neurofibromatosis 1. Neuro- oncology. 2008;10(4):593-8. 109. Khong PL, Goh WH, Wong VC, Fung CW, Ooi GC. MR imaging of spinal tumors in children with neurofibromatosis 1. AJR American journal of roentgenology. 2003;180(2):413-7. 110. Upadhyaya M, Spurlock G, Kluwe L, Chuzhanova N, Bennett E, Thomas N, et al. The spectrum of somatic and germline NF1 mutations in NF1 patients with spinal neurofibromas. Neurogenetics. 2009;10(3):251-63. 111. Thakkar SD, Feigen U, Mautner VF. Spinal tumours in neurofibromatosis type 1: an MRI study of frequency, multiplicity and variety. Neuroradiology. 1999;41(9):625-9.

203 112. Sbidian E, Hadj-Rabia S, Riccardi VM, Valeyrie-Allanore LL, Barbarot S, Chosidow O, et al. Clinical characteristics predicting internal neurofibromas in 357 children with neurofibromatosis-1: results from a cross-selectional study. Orphanet journal of rare diseases. 2012;7:62. 113. Grattan-Smith PJ, Ryan MM, Procopis PG. Persistent or severe back pain and stiffness are ominous symptoms requiring prompt attention. Journal of paediatrics and child health. 2000;36(3):208-12. 114. Buck E, Bodensteiner J. Thoracic cord tumor appearing as recurrent abdominal pain. American journal of diseases of children. 1981;135(6):574-5. 115. Poretti A, Zehnder D, Boltshauser E, Grotzer MA. Long-term complications and quality of life in children with intraspinal tumors. Pediatric blood & cancer. 2008;50(4):844-8. 116. Varalakshmi V, Idowu A, Jeevan S. Spinal tumour: a diagnostic lesson. Journal of accident & emergency medicine. 1998;15(3):199. 117. Pratap A, Nepal P, Agrawal A, Singh MP, Pandey SR. Giant malignant nerve sheath tumor of lumbosacral plexus with intraspinal extension in a child with neurofibromatosis type 1. Pediatric neurosurgery. 2007;43(5):410-3. 118. Tsirikos AI, Saifuddin A, Noordeen MH. Spinal deformity in neurofibromatosis type-1: diagnosis and treatment. European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society. 2005;14(5):427-39. 119. Winter RB, Moe JH, Bradford DS, Lonstein JE, Pedras CV, Weber AH. Spine deformity in neurofibromatosis. A review of one hundred and two patients. The Journal of bone and joint surgery American volume. 1979;61(5):677-94. 120. Crawford AH, Parikh S, Schorry EK, Von Stein D. The immature spine in type-1 neurofibromatosis. The Journal of bone and joint surgery American volume. 2007;89 Suppl 1:123-42. 121. Ramachandran M, Tsirikos AI, Lee J, Saifuddin A. Whole-spine magnetic resonance imaging in patients with neurofibromatosis type 1 and spinal deformity. Journal of spinal disorders & techniques. 2004;17(6):483-91. 122. Papagelopoulos PJ, Peterson HA, Ebersold MJ, Emmanuel PR, Choudhury SN, Quast LM. Spinal column deformity and instability after lumbar or thoracolumbar laminectomy for intraspinal tumors in children and young adults. Spine. 1997;22(4):442-51. 123. Egelhoff JC, Bates DJ, Ross JS, Rothner AD, Cohen BH. Spinal MR findings in neurofibromatosis types 1 and 2. AJNR American journal of neuroradiology. 1992;13(4):1071- 7. 124. Dombi E, Ardern-Holmes SL, Babovic-Vuksanovic D, Barker FG, Connor S, Evans DG, et al. Recommendations for imaging tumor response in neurofibromatosis clinical trials. Neurology. 2013;81(21 Suppl 1):S33-40. 125. Van Meerbeeck SF, Verstraete KL, Janssens S, Mortier G. Whole body MR imaging in neurofibromatosis type 1. European journal of radiology. 2009;69(2):236-42. 126. Cai W, Kassarjian A, Bredella MA, Harris GJ, Yoshida H, Mautner VF, et al. Tumor burden in patients with neurofibromatosis types 1 and 2 and schwannomatosis: determination on whole- body MR images. Radiology. 2009;250(3):665-73. 127. Nguyen R, Dombi E, Akshintala S, Baldwin A, Widemann BC. Characterization of spinal findings in children and adults with neurofibromatosis type 1 enrolled in a natural history study using magnetic resonance imaging. Journal of neuro-oncology. 2015;121(1):209-15. 128. Lee M, Rezai AR, Freed D, Epstein FJ. Intramedullary spinal cord tumors in neurofibromatosis. Neurosurgery. 1996;38(1):32-7. 129. Jacques C, Dietemann JL. [Imaging features of neurofibromatosis type 1]. Journal of neuroradiology Journal de neuroradiologie. 2005;32(3):180-97. 130. Ruggieri M, Polizzi A, Spalice A, Salpietro V, Caltabiano R, D'Orazi V, et al. The natural history of spinal neurofibromatosis: a critical review of clinical and genetic features. Clinical genetics. 2015;87(5):401-10. 131. Klekamp J, Samii M. Surgery of spinal nerve sheath tumors with special reference to neurofibromatosis. Neurosurgery. 1998;42(2):279-89; discussion 89-90. 132. Demestre M, Herzberg J, Holtkamp N, Hagel C, Reuss D, Friedrich RE, et al. Imatinib mesylate (Glivec) inhibits Schwann cell viability and reduces the size of human plexiform neurofibroma in a xenograft model. Journal of neuro-oncology. 2010;98(1):11-9.

204 133. Chamoun RB, Whitehead WE, Dauser RC, Luerssen TG, Okcu MF, Adesina AM, et al. Primary disseminated intradural malignant peripheral nerve sheath tumor of the spine in a child: case report and review of the literature. Pediatric neurosurgery. 2009;45(3):230-6. 134. Warbey VS, Ferner RE, Dunn JT, Calonje E, O'Doherty MJ. [18F]FDG PET/CT in the diagnosis of malignant peripheral nerve sheath tumours in neurofibromatosis type-1. European journal of nuclear medicine and molecular imaging. 2009;36(5):751-7. 135. Plotkin SR, Albers AC, Babovic-Vuksanovic D, Blakeley JO, Breakefield XO, Dunn CM, et al. Update from the 2013 International Neurofibromatosis Conference. American journal of medical genetics Part A. 2014;164A(12):2969-78. 136. Tucker T, Friedman JM, Friedrich RE, Wenzel R, Funsterer C, Mautner VF. Longitudinal study of neurofibromatosis 1 associated plexiform neurofibromas. Journal of medical genetics. 2009;46(2):81-5. 137. Canavese F, Krajbich JI. Resection of plexiform neurofibromas in children with neurofibromatosis type 1. J Pediatr Orthop. 2011;31(3):303-11. 138. Kim A, Dombi E, Tepas K, Fox E, Martin S, Wolters P, et al. Phase I trial and pharmacokinetic study of sorafenib in children with neurofibromatosis type I and plexiform neurofibromas. Pediatric blood & cancer. 2013;60(3):396-401. 139. Babovic-Vuksanovic D, Widemann BC, Dombi E, Gillespie A, Wolters PL, Toledo-Tamula MA, et al. Phase I trial of pirfenidone in children with neurofibromatosis 1 and plexiform neurofibromas. Pediatric neurology. 2007;36(5):293-300. 140. Solomon J, Warren K, Dombi E, Patronas N, Widemann B. Automated detection and volume measurement of plexiform neurofibromas in neurofibromatosis 1 using magnetic resonance imaging. Comput Med Imaging Graph. 2004;28(5):257-65. 141. Yang FC, Ingram DA, Chen S, Zhu Y, Yuan J, Li X, et al. Nf1-dependent tumors require a microenvironment containing Nf1+/-- and c-kit-dependent bone marrow. Cell. 2008;135(3):437- 48. 142. Staser K, Yang FC, Clapp DW. Mast cells and the neurofibroma microenvironment. Blood. 2010;116(2):157-64. 143. Lee JL, Kim JY, Ryu MH, Kang HJ, Chang HM, Kim TW, et al. Response to imatinib in KIT- and PDGFRA-wild type gastrointestinal stromal associated with neurofibromatosis type 1. Dig Dis Sci. 2006;51(6):1043-6. 144. McHorney CA, Ware JE, Jr., Raczek AE. The MOS 36-Item Short-Form Health Survey (SF- 36): II. Psychometric and clinical tests of validity in measuring physical and mental health constructs. Medical care. 1993;31(3):247-63. 145. Ware JE, Jr., Gandek B. Overview of the SF-36 Health Survey and the International Quality of Life Assessment (IQOLA) Project. Journal of clinical epidemiology. 1998;51(11):903-12. 146. Fayers PM, D. . Quality of Life (Second Edition): The assessment, analysis and interpretation of patient-reported outcomes.: John Wiley and Sons 2007. 147. National Health Survey: SF36 Population Norms, Australia. Canberra, Australia: Australian Bureau of Statistics. 1995. 148. Wolkenstein P, Zeller J, Revuz J, Ecosse E, Leplege A. Quality-of-life impairment in neurofibromatosis type 1: a cross-sectional study of 128 cases. Archives of dermatology. 2001;137(11):1421-5. 149. Korf BR. Spinal neurofibromatosis and phenotypic heterogeneity in NF1. Clinical genetics. 2015;87(5):399-400. 150. Kluwe L, Nguyen R, Vogt J, Bengesser K, Mussotter T, Friedrich RE, et al. Internal tumor burden in neurofibromatosis Type I patients with large NF1 deletions. Genes, chromosomes & cancer. 2012;51(5):447-51. 151. Plotkin SR, Davis SD, Robertson KA, Akshintala S, Allen J, Fisher MJ, et al. Sleep and pulmonary outcomes for clinical trials of airway plexiform neurofibromas in NF1. Neurology. 2016;87(7 Suppl 1):S13-20. 152. Wolters PL, Martin S, Merker VL, Tonsgard JH, Solomon SE, Baldwin A, et al. Patient- reported outcomes of pain and physical functioning in neurofibromatosis clinical trials. Neurology. 2016;87(7 Suppl 1):S4-S12. 153. Varni JW, Seid M, Kurtin PS. PedsQL 4.0: reliability and validity of the Pediatric Quality of Life Inventory version 4.0 generic core scales in healthy and patient populations. Medical care. 2001;39(8):800-12. 154. Wolters P, Martin, SC., Tamula MA, Development of a quality of life scale for children with chronic illness with CNS involvement:preliminary data [abstract]. . Development of a quality of

205 life scale for children with chronic illness with CNS involvement:preliminary data Neurooncology. 2004:6. 155. Vranceanu AM, Merker VL, Park ER, Plotkin SR. Quality of life among children and adolescents with neurofibromatosis 1: a systematic review of the literature. Journal of neuro- oncology. 2015;122(2):219-28. 156. Mautner VF, Nguyen, R., Ardern-Holmes, S.L., Kluwe, L., Renard, M., Clarke, N., Denayer, E., Valeyrie-Allanore, L., Wolkenstein, P., Legius, E. . Imatinib did not induce regression of plexiform neurofibromas in 7 pediatric NF1 patients. . Blood 2011; . 157. Millot F BA, Guilhot J. et al. Imatinib is efficient but has negative impact on growth in children with previously untreated chronic myelogenous leukaemia (CML) in early chronic phase (CP):Resuls of the French National Phase IV Trial. . 2009. 158. Jessen WJ, Miller SJ, Jousma E, Wu J, Rizvi TA, Brundage ME, et al. MEK inhibition exhibits efficacy in human and mouse neurofibromatosis tumors. J Clin Invest. 2013;123(1):340-7. 159. Jousma E, Rizvi TA, Wu J, Janhofer D, Dombi E, Dunn RS, et al. Preclinical assessments of the MEK inhibitor PD-0325901 in a mouse model of Neurofibromatosis type 1. Pediatric blood & cancer. 2015;62(10):1709-16. 160. Infante JR, Fecher LA, Falchook GS, Nallapareddy S, Gordon MS, Becerra C, et al. Safety, pharmacokinetic, pharmacodynamic, and efficacy data for the oral MEK inhibitor trametinib: a phase 1 dose-escalation trial. The Lancet Oncology. 2012;13(8):773-81. 161. Evans DG, Huson SM, Donnai D, Neary W, Blair V, Teare D, et al. A genetic study of type 2 neurofibromatosis in the United Kingdom. I. Prevalence, mutation rate, fitness, and confirmation of maternal transmission effect on severity. Journal of medical genetics. 1992;29(12):841-6. 162. MacCollin M, Mautner VF. The diagnosis and management of neurofibromatosis 2 in childhood. Seminars in pediatric neurology. 1998;5(4):243-52. 163. Mautner VF, Lindenau M, Baser ME, Hazim W, Tatagiba M, Haase W, et al. The neuroimaging and clinical spectrum of neurofibromatosis 2. Neurosurgery. 1996;38(5):880-5; discussion 5-6. 164. Nunes F, MacCollin M. Neurofibromatosis 2 in the Pediatric Population. Journal of Child Neurology. 2003;18(10):718-24. 165. Evans DG, Huson SM, Donnai D, Neary W, Blair V, Newton V, et al. A clinical study of type 2 neurofibromatosis. The Quarterly journal of medicine. 1992;84(304):603-18. 166. Evans DG. Neurofibromatosis 2 [Bilateral acoustic neurofibromatosis, central neurofibromatosis, NF2, neurofibromatosis type II]. Genetics in medicine : official journal of the American College of Medical Genetics. 2009;11(9):599-610. 167. Asthagiri AR, Parry DM, Butman JA, Kim HJ, Tsilou ET, Zhuang Z, et al. Neurofibromatosis type 2. Lancet. 2009;373(9679):1974-86. 168. Bosch MM, Boltshauser E, Harpes P, Landau K. Ophthalmologic findings and long-term course in patients with neurofibromatosis type 2. American journal of ophthalmology. 2006;141(6):1068-77. 169. Rouleau GA, Wertelecki W, Haines JL, Hobbs WJ, Trofatter JA, Seizinger BR, et al. Genetic linkage of bilateral acoustic neurofibromatosis to a DNA marker on chromosome 22. Nature. 1987;329(6136):246-8. 170. Lee JY, Kim H, Ryu CH, Kim JY, Choi BH, Lim Y, et al. Merlin, a tumor suppressor, interacts with transactivation-responsive RNA-binding protein and inhibits its oncogenic activity. The Journal of biological chemistry. 2004;279(29):30265-73. 171. Hanemann CO. Magic but treatable? Tumours due to loss of merlin. Brain : a journal of neurology. 2008;131(Pt 3):606-15. 172. Evans DG, Maher ER, Baser ME. Age related shift in the mutation spectra of germline and somatic NF2 mutations: hypothetical role of DNA repair mechanisms. Journal of medical genetics. 2005;42(8):630-2. 173. Warren C, James LA, Ramsden RT, Wallace A, Baser ME, Varley JM, et al. Identification of recurrent regions of chromosome loss and gain in vestibular schwannomas using comparative genomic hybridisation. Journal of medical genetics. 2003;40(11):802-6. 174. Kluwe L, Mautner V, Heinrich B, Dezube R, Jacoby LB, Friedrich RE, et al. Molecular study of frequency of mosaicism in neurofibromatosis 2 patients with bilateral vestibular schwannomas. Journal of medical genetics. 2003;40(2):109-14. 175. Lloyd SK, Evans DG. Neurofibromatosis type 2 (NF2): diagnosis and management. Handbook of clinical neurology. 2013;115:957-67.

206 176. Ahronowitz I, Xin W, Kiely R, Sims K, MacCollin M, Nunes FP. Mutational spectrum of the NF2 gene: a meta-analysis of 12 years of research and diagnostic laboratory findings. Human mutation. 2007;28(1):1-12. 177. Evans DG, Sainio M, Baser ME. Neurofibromatosis type 2. Journal of medical genetics. 2000;37(12):897-904. 178. Evans DG, Ramsden RT, Gokhale C, Bowers N, Huson SM, Wallace A. Should NF2 mutation screening be undertaken in patients with an apparently isolated vestibular schwannoma? Clinical genetics. 2007;71(4):354-8. 179. Ruggieri M, Iannetti P, Polizzi A, La Mantia I, Spalice A, Giliberto O, et al. Earliest clinical manifestations and natural history of neurofibromatosis type 2 (NF2) in childhood: a study of 24 patients. Neuropediatrics. 2005;36(1):21-34. 180. Baser ME, Friedman JM, Aeschliman D, Joe H, Wallace AJ, Ramsden RT, et al. Predictors of the risk of mortality in neurofibromatosis 2. American journal of human genetics. 2002;71(4):715-23. 181. Patronas NJ, Courcoutsakis N, Bromley CM, Katzman GL, MacCollin M, Parry DM. Intramedullary and spinal canal tumors in patients with neurofibromatosis 2: MR imaging findings and correlation with genotype. Radiology. 2001;218(2):434-42. 182. Smith MJ, Higgs JE, Bowers NL, Halliday D, Paterson J, Gillespie J, et al. Cranial meningiomas in 411 neurofibromatosis type 2 (NF2) patients with proven gene mutations: clear positional effect of mutations, but absence of female severity effect on age at onset. Journal of medical genetics. 2011;48(4):261-5. 183. Selvanathan SK, Shenton A, Ferner R, Wallace AJ, Huson SM, Ramsden RT, et al. Further genotype--phenotype correlations in neurofibromatosis 2. Clinical genetics. 2010;77(2):163-70. 184. Barbi G, Rossier E, Vossbeck S, Hummler H, Lang D, Flock F, et al. Constitutional de novo interstitial deletion of 8 Mb on chromosome 22q12.1-12.3 encompassing the neurofibromatosis type 2 (NF2) locus in a dysmorphic girl with severe malformations. Journal of medical genetics. 2002;39(2):E6. 185. Mautner VF. Spinal tumors in patients with neurofibromatosis type 2: MR imaging study of frequency, multiplicity and variety. AJR American journal of roentgenology. 1996;166(5):1231. 186. Hoa M, Slattery WH, 3rd. Neurofibromatosis 2. Otolaryngologic clinics of North America. 2012;45(2):315-32, viii. 187. Merker VL, Bredella MA, Cai W, Kassarjian A, Harris GJ, Muzikansky A, et al. Relationship between whole-body tumor burden, clinical phenotype, and quality of life in patients with neurofibromatosis. American journal of medical genetics Part A. 2014;164A(6):1431-7. 188. Baser ME, Evans DG, Jackler RK, Sujansky E, Rubenstein A. Neurofibromatosis 2, radiosurgery and malignant nervous system tumours. British journal of cancer. 2000;82(4):998. 189. Evans DG, Birch JM, Ramsden RT, Sharif S, Baser ME. Malignant transformation and new primary tumours after therapeutic radiation for benign disease: substantial risks in certain tumour prone syndromes. Journal of medical genetics. 2006;43(4):289-94. 190. Evans DG, Moran A, King A, Saeed S, Gurusinghe N, Ramsden R. Incidence of vestibular schwannoma and neurofibromatosis 2 in the North West of England over a 10-year period: higher incidence than previously thought. Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 2005;26(1):93-7. 191. Otsuka G, Saito K, Nagatani T, Yoshida J. Age at symptom onset and long-term survival in patients with neurofibromatosis Type 2. Journal of neurosurgery. 2003;99(3):480-3. 192. Evans DG, Lye R, Neary W, Black G, Strachan T, Wallace A, et al. Probability of bilateral disease in people presenting with a unilateral vestibular schwannoma. Journal of neurology, neurosurgery, and psychiatry. 1999;66(6):764-7. 193. Goutagny S, Kalamarides M. Meningiomas and neurofibromatosis. Journal of neuro-oncology. 2010;99(3):341-7. 194. Goutagny S, Bah AB, Henin D, Parfait B, Grayeli AB, Sterkers O, et al. Long-term follow-up of 287 meningiomas in neurofibromatosis type 2 patients: clinical, radiological, and molecular features. Neuro-oncology. 2012;14(8):1090-6. 195. Perry A, Giannini C, Raghavan R, Scheithauer BW, Banerjee R, Margraf L, et al. Aggressive phenotypic and genotypic features in pediatric and NF2-associated meningiomas: a clinicopathologic study of 53 cases. Journal of neuropathology and experimental neurology. 2001;60(10):994-1003.

207 196. Dirks MS, Butman JA, Kim HJ, Wu T, Morgan K, Tran AP, et al. Long-term natural history of neurofibromatosis Type 2-associated intracranial tumors. Journal of neurosurgery. 2012;117(1):109-17. 197. Bosch MM, Wichmann WW, Boltshauser E, Landau K. Optic nerve sheath meningiomas in patients with neurofibromatosis type 2. Archives of ophthalmology. 2006;124(3):379-85. 198. Harold Lee HB, Garrity JA, Cameron JD, Strianese D, Bonavolonta G, Patrinely JR. Primary optic nerve sheath meningioma in children. Survey of ophthalmology. 2008;53(6):543-58. 199. Evans DG, Watson C, King A, Wallace AJ, Baser ME. Multiple meningiomas: differential involvement of the NF2 gene in children and adults. Journal of medical genetics. 2005;42(1):45- 8. 200. Evans DG. Neurofibromatosis type 2 (NF2): a clinical and molecular review. Orphanet journal of rare diseases. 2009;4:16. 201. Mautner VF, Tatagiba M, Lindenau M, Funsterer C, Pulst SM, Baser ME, et al. Spinal tumors in patients with neurofibromatosis type 2: MR imaging study of frequency, multiplicity, and variety. AJR American journal of roentgenology. 1995;165(4):951-5. 202. Hagel C, Stemmer-Rachamimov AO, Bornemann A, Schuhmann M, Nagel C, Huson S, et al. Clinical presentation, immunohistochemistry and electron microscopy indicate neurofibromatosis type 2-associated gliomas to be spinal ependymomas. Neuropathology : official journal of the Japanese Society of Neuropathology. 2012;32(6):611-6. 203. Parry DM, Eldridge R, Kaiser-Kupfer MI, Bouzas EA, Pikus A, Patronas N. Neurofibromatosis 2 (NF2): clinical characteristics of 63 affected individuals and clinical evidence for heterogeneity. American journal of medical genetics. 1994;52(4):450-61. 204. Mautner VF, Lindenau M, Baser ME, Kluwe L, Gottschalk J. Skin abnormalities in neurofibromatosis 2. Archives of dermatology. 1997;133(12):1539-43. 205. Cruz MJ, Baudrier T, Gil-Da-Costa MJ, Azevedo F, Mota A. Multiple cutaneous plexiform schwannomas revealing neurofibromatosis type 2 in a child - report of a novel mutation in this rare association. European journal of dermatology : EJD. 2011;21(6):1010-1. 206. Mautner VF, Tatagiba M, Guthoff R, Samii M, Pulst SM. Neurofibromatosis 2 in the pediatric age group. Neurosurgery. 1993;33(1):92-6. 207. Ragge NK, Baser ME, Riccardi VM, Falk RE. The ocular presentation of neurofibromatosis 2. Eye. 1997;11 ( Pt 1):12-8. 208. Bouzas EA, Parry DM, Eldridge R, Kaiser-Kupfer MI. Visual impairment in patients with neurofibromatosis 2. Neurology. 1993;43(3 Pt 1):622-3. 209. Feucht M, Griffiths B, Niemuller I, Haase W, Richard G, Mautner VF. Neurofibromatosis 2 leads to higher incidence of strabismological and neuro-ophthalmological disorders. Acta ophthalmologica. 2008;86(8):882-6. 210. Kaye LD, Rothner AD, Beauchamp GR, Meyers SM, Estes ML. Ocular findings associated with neurofibromatosis type II. Ophthalmology. 1992;99(9):1424-9. 211. Sisk RA, Berrocal AM, Schefler AC, Dubovy SR, Bauer MS. Epiretinal membranes indicate a severe phenotype of neurofibromatosis type 2. Retina. 2010;30(4 Suppl):S51-8. 212. Sperfeld AD, Hein C, Schroder JM, Ludolph AC, Hanemann CO. Occurrence and characterization of peripheral nerve involvement in neurofibromatosis type 2. Brain : a journal of neurology. 2002;125(Pt 5):996-1004. 213. Hagel C, Lindenau M, Lamszus K, Kluwe L, Stavrou D, Mautner VF. Polyneuropathy in neurofibromatosis 2: clinical findings, molecular genetics and neuropathological alterations in sural nerve biopsy specimens. Acta neuropathologica. 2002;104(2):179-87. 214. Plotkin SR, Ardern-Holmes SL, Barker FG, 2nd, Blakeley JO, Evans DG, Ferner RE, et al. Hearing and facial function outcomes for neurofibromatosis 2 clinical trials. Neurology. 2013;81(21 Suppl 1):S25-32. 215. Harris GJ, Plotkin SR, Maccollin M, Bhat S, Urban T, Lev MH, et al. Three-dimensional volumetrics for tracking vestibular schwannoma growth in neurofibromatosis type II. Neurosurgery. 2008;62(6):1314-9; discussion 9-20. 216. Slattery WH, 3rd, Fisher LM, Iqbal Z, Oppenhiemer M. Vestibular schwannoma growth rates in neurofibromatosis type 2 natural history consortium subjects. Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 2004;25(5):811-7. 217. Fisher LM, Doherty JK, Lev MH, Slattery WH. Concordance of bilateral vestibular schwannoma growth and hearing changes in neurofibromatosis 2: neurofibromatosis 2 natural history consortium. Otology & neurotology : official publication of the American Otological

208 Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 2009;30(6):835-41. 218. Plotkin SR, Merker VL, Muzikansky A, Barker FG, 2nd, Slattery W, 3rd. Natural history of vestibular schwannoma growth and hearing decline in newly diagnosed neurofibromatosis type 2 patients. Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 2014;35(1):e50-6. 219. Blakeley JO, Evans DG, Adler J, Brackmann D, Chen R, Ferner RE, et al. Consensus recommendations for current treatments and accelerating clinical trials for patients with neurofibromatosis type 2. American journal of medical genetics Part A. 2012;158A(1):24-41. 220. Evans DG. Neurofibromatosis type 2: genetic and clinical features. Ear, nose, & throat journal. 1999;78(2):97-100. 221. Choi JW, Lee JY, Phi JH, Wang KC, Chung HT, Paek SH, et al. Clinical course of vestibular schwannoma in pediatric neurofibromatosis Type 2. Journal of neurosurgery Pediatrics. 2014;13(6):650-7. 222. Stachowicz-Stencel T, Synakiewicz A, Bien E, Adamkiewicz-Drozynska E, Wybieralska- Dubaniewicz M, Balcerska A. Multiple primary cranio-spinal tumours in a 13-year-old female with neurofibromatosis type 2 management strategy. Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery. 2011;27(1):175-8. 223. Janse AJ, Tan WF, Majoie CB, Bijlsma EK. Neurofibromatosis type 2 diagnosed in the absence of vestibular schwannomas. A case report and guidelines for a screening protocol for children at risk. European journal of pediatrics. 2001;160(7):439-43. 224. . 225. Widemann BC, Acosta MT, Ammoun S, Belzberg AJ, Bernards A, Blakeley J, et al. CTF meeting 2012: Translation of the basic understanding of the biology and genetics of NF1, NF2, and schwannomatosis toward the development of effective therapies. American journal of medical genetics Part A. 2014;164A(3):563-78. 226. Kalamarides M, Acosta MT, Babovic-Vuksanovic D, Carpen O, Cichowski K, Evans DG, et al. Neurofibromatosis 2011: a report of the Children's Tumor Foundation annual meeting. Acta neuropathologica. 2012;123(3):369-80. 227. Mautner VF, Nguyen R, Kutta H, Fuensterer C, Bokemeyer C, Hagel C, et al. Bevacizumab induces regression of vestibular schwannomas in patients with neurofibromatosis type 2. Neuro- oncology. 2010;12(1):14-8. 228. Plotkin SR, Merker VL, Halpin C, Jennings D, McKenna MJ, Harris GJ, et al. Bevacizumab for progressive vestibular schwannoma in neurofibromatosis type 2: a retrospective review of 31 patients. Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 2012;33(6):1046-52. 229. Goutagny S, Raymond E, Sterkers O, Colombani JM, Kalamarides M. Radiographic regression of cranial meningioma in a NF2 patient treated by bevacizumab. Annals of oncology : official journal of the European Society for Medical Oncology / ESMO. 2011;22(4):990-1. 230. Farschtschi S, Merker VL, Wolf D, Schuhmann M, Blakeley J, Plotkin SR, et al. Bevacizumab treatment for symptomatic spinal ependymomas in neurofibromatosis type 2. Acta neurologica Scandinavica. 2016;133(6):475-80. 231. Plotkin SR, Albers AC, Babovic-Vuksanovic D, Blakeley JO, Breakefield XO, Dunn CM, et al. Update from the 2013 international neurofibromatosis conference. American journal of medical genetics Part A. 2014. 232. MacNally SP, Rutherford SA, King AT, Freeman S, Thorne J, Mawman D, et al. Outcome from surgery for vestibular schwannomas in children. British journal of neurosurgery. 2009;23(3):226-31. 233. Jaaskelainen J, Paetau A, Pyykko I, Blomstedt G, Palva T, Troupp H. Interface between the facial nerve and large acoustic neurinomas. Immunohistochemical study of the cleavage plane in NF2 and non-NF2 cases. Journal of neurosurgery. 1994;80(3):541-7. 234. Friedman RA, Goddard JC, Wilkinson EP, Schwartz MS, Slattery WH, 3rd, Fayad JN, et al. Hearing preservation with the middle cranial fossa approach for neurofibromatosis type 2. Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 2011;32(9):1530- 7.

209 235. Neff BA, Wiet RM, Lasak JM, Cohen NL, Pillsbury HC, Ramsden RT, et al. Cochlear implantation in the neurofibromatosis type 2 patient: long-term follow-up. The Laryngoscope. 2007;117(6):1069-72. 236. Slattery WH, 3rd, Fisher LM, Hitselberger W, Friedman RA, Brackmann DE. Hearing preservation surgery for neurofibromatosis Type 2-related vestibular schwannoma in pediatric patients. Journal of neurosurgery. 2007;106(4 Suppl):255-60. 237. Mathieu D, Kondziolka D, Flickinger JC, Niranjan A, Williamson R, Martin JJ, et al. Stereotactic radiosurgery for vestibular schwannomas in patients with neurofibromatosis type 2: an analysis of tumor control, complications, and hearing preservation rates. Neurosurgery. 2007;60(3):460-8; discussion 8-70. 238. Rowe JG, Radatz MW, Walton L, Soanes T, Rodgers J, Kemeny AA. Clinical experience with gamma knife stereotactic radiosurgery in the management of vestibular schwannomas secondary to type 2 neurofibromatosis. Journal of neurology, neurosurgery, and psychiatry. 2003;74(9):1288-93. 239. Baser ME, DG RE, Gutmann DH. Neurofibromatosis 2. Current opinion in neurology. 2003;16(1):27-33. 240. Goodman A. Reference zero levels for pure-tone audiometer. . ASHA. 1965;7:262-3. 241. Ardern-Holmes S, Fisher G, North K. Neurofibromatosis Type 2: Presentation, Major Complications, and Management, With a Focus on the Pediatric Age Group. J Child Neurol. 2016. 242. Bonne N, Aboukais R, Baroncini M, Hochart A, Leblond P, Broly F, et al. Pediatric neurofibromatosis type 2: clinical and molecular presentation, management of vestibular schwannomas, and hearing rehabilitation. Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery. 2016;32(12):2403-13. 243. Schwartz RA, Fernandez G, Kotulska K, Jozwiak S. Tuberous sclerosis complex: advances in diagnosis, genetics, and management. Journal of the American Academy of Dermatology. 2007;57(2):189-202. 244. Davidson TB, Sanchez-Lara PA, Randolph LM, Krieger MD, Wu SQ, Panigrahy A, et al. Microdeletion del(22)(q12.2) encompassing the facial development-associated gene, MN1 (meningioma 1) in a child with Pierre-Robin sequence (including cleft palate) and neurofibromatosis 2 (NF2): a case report and review of the literature. BMC Med Genet. 2012;13:19. 245. Patel CM, Ferner R, Grunfeld EA. A qualitative study of the impact of living with neurofibromatosis type 2. Psychology, health & medicine. 2011;16(1):19-28. 246. Merker VL, Bergner AL, Vranceanu AM, Muzikansky A, Slattery W, 3rd, Plotkin SR. Health- related Quality of Life of Individuals With Neurofibromatosis Type 2: Results From the NF2 Natural History Study. Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 2016;37(5):574-9. 247. Ferner RE, Shaw A, Evans DG, McAleer D, Halliday D, Parry A, et al. Longitudinal evaluation of quality of life in 288 patients with neurofibromatosis 2. J Neurol. 2014;261(5):963-9. 248. Hochart A, Gaillard V, Baroncini M, Andre N, Vannier JP, Vinchon M, et al. Bevacizumab decreases vestibular schwannomas growth rate in children and teenagers with neurofibromatosis type 2. Journal of neuro-oncology. 2015;124(2):229-36. 249. Katrina A. Morris JFG, Patrick R. Axon, Shazia Afridi, Claire Blesing, Rosalie E. Ferner, Dorothy Halliday, Raj Jena, Pieter M. Pretorius, the UK NF2 Research group, D. Gareth Evans, Martin G. McCabe, and Allyson Parry. Bevacizumab in neurofibromatosis type 2 (NF2) related vestibular schwannomas: a nationally coordinated approach to delivery and prospective evaluation. Neuro Oncol Pract 2016;3(4): 281-9. 250. Ramsden RT, Freeman SR, Lloyd SK, King AT, Shi X, Ward CL, et al. Auditory Brainstem Implantation in Neurofibromatosis Type 2: Experience From the Manchester Programme. Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 2016;37(9):1267- 74. 251. Lassaletta L, Aristegui M, Medina M, Aranguez G, Perez-Mora RM, Falcioni M, et al. Ipsilateral cochlear implantation in patients with sporadic vestibular schwannoma in the only or best hearing ear and in patients with NF2. European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies. 2016;273(1):27-35.

210 252. North HJ, Mawman D, O'Driscoll M, Freeman SR, Rutherford SA, King AT, et al. Outcomes of cochlear implantation in patients with neurofibromatosis type 2. Cochlear implants international. 2016;17(4):172-7. 253. Xiao GH, Chernoff J, Testa JR. NF2: the wizardry of merlin. Genes, chromosomes & cancer. 2003;38(4):389-99. 254. Anonymous. Committee on Hearing and Equilibrium guidelines for the evaluation of hearing preservation in acoustic neuroma (vestibular schwannoma). . Otolaryngology-Head and Neck Surgery. 1995;114:179-80. 255. Gatehouse S, Noble W. The Speech, Spatial and Qualities of Hearing Scale (SSQ). International journal of audiology. 2004;43(2):85-99. 256. Akeroyd MA, Guy FH, Harrison DL, Suller SL. A factor analysis of the SSQ (Speech, Spatial, and Qualities of Hearing Scale). International journal of audiology. 2014;53(2):101-14. 257. Douglas SA, Yeung P, Daudia A, Gatehouse S, O'Donoghue GM. Spatial hearing disability after acoustic neuroma removal. The Laryngoscope. 2007;117(9):1648-51. 258. Ahlstrom JB, Horwitz AR, Dubno JR. Spatial benefit of bilateral hearing AIDS. Ear and hearing. 2009;30(2):203-18. 259. Vermeire K, Van de Heyning P. Binaural hearing after cochlear implantation in subjects with unilateral sensorineural deafness and tinnitus. Audiology & neuro-otology. 2009;14(3):163-71. 260. Martin TP, Lowther R, Cooper H, Holder RL, Irving RM, Reid AP, et al. The bone-anchored hearing aid in the rehabilitation of single-sided deafness: experience with 58 patients. Clinical otolaryngology : official journal of ENT-UK ; official journal of Netherlands Society for Oto- Rhino-Laryngology & Cervico-Facial Surgery. 2010;35(4):284-90. 261. Cheng S, Naidoo Y, da Cruz M, Dexter M. Quality of life in postoperative vestibular schwannoma patients. Laryngoscope. 2009;119(11):2252-7. 262. Myrseth E, Moller P, Wentzel-Larsen T, Goplen F, Lund-Johansen M. Untreated vestibular schwannomas: vertigo is a powerful predictor for health-related quality of life. Neurosurgery. 2006;59(1):67-76; discussion 67-76. 263. Neary WJ, Hillier VF, Flute T, Stephens SD, Ramsden RT, Evans DG. The relationship between patients' perception of the effects of neurofibromatosis type 2 and the domains of the Short Form-36. Clinical otolaryngology : official journal of ENT-UK ; official journal of Netherlands Society for Oto-Rhino-Laryngology & Cervico-Facial Surgery. 2010;35(4):291-9. 264. Cosetti MK, Golfinos JG, Roland JT, Jr. Quality of Life (QoL) Assessment in Patients with Neurofibromatosis Type 2 (NF2). Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery. 2015;153(4):599-605. 265. Neary WJ, Hillier VF, Flute T, Stephens D, Ramsden RT, Evans DG. Use of a closed set questionnaire to measure primary and secondary effects of neurofibromatosis type 2. The Journal of laryngology and otology. 2010;124(7):720-8. 266. Coates A, Gebski V, Bishop JF, Jeal PN, Woods RL, Snyder R, et al. Improving the quality of life during chemotherapy for advanced breast cancer. A comparison of intermittent and continuous treatment strategies. The New England journal of medicine. 1987;317(24):1490-5. 267. Locke DE, Decker PA, Sloan JA, Brown PD, Malec JF, Clark MM, et al. Validation of single- item linear analog scale assessment of quality of life in neuro-oncology patients. Journal of pain and symptom management. 2007;34(6):628-38. 268. Noble W, Jensen NS, Naylor G, Bhullar N, Akeroyd MA. A short form of the Speech, Spatial and Qualities of Hearing scale suitable for clinical use: the SSQ12. International journal of audiology. 2013;52(6):409-12. 269. Galvin KL, Noble W. Adaptation of the speech, spatial, and qualities of hearing scale for use with children, parents, and teachers. Cochlear implants international. 2013;14(3):135-41. 270. da Cruz MJ, Moffat DA, Hardy DG. Postoperative quality of life in vestibular schwannoma patients measured by the SF36 Health Questionnaire. The Laryngoscope. 2000;110(1):151-5. 271. Evans DG, Bowers N, Huson SM, Wallace A. Mutation type and position varies between mosaic and inherited NF2 and correlates with disease severity. Clinical genetics. 2013;83(6):594-5. 272. Niranjan A, Mathieu D, Flickinger JC, Kondziolka D, Lunsford LD. Hearing preservation after intracanalicular vestibular schwannoma radiosurgery. Neurosurgery. 2008;63(6):1054-62; discussion 62-3. 273. Phi JH, Kim DG, Chung HT, Lee J, Paek SH, Jung HW. Radiosurgical treatment of vestibular schwannomas in patients with neurofibromatosis type 2: tumor control and hearing preservation. Cancer. 2009;115(2):390-8.

211 274. Bari ME, Forster DM, Kemeny AA, Walton L, Hardy D, Anderson JR. Malignancy in a vestibular schwannoma. Report of a case with central neurofibromatosis, treated by both stereotactic radiosurgery and surgical excision, with a review of the literature. Br J Neurosurg. 2002;16(3):284-9. 275. Newton HB. Molecular neuro-oncology and development of targeted therapeutic strategies for brain tumors. Part 2: PI3K/Akt/PTEN, mTOR, SHH/PTCH and angiogenesis. Expert review of anticancer therapy. 2004;4(1):105-28. 276. Halpin C, Rauch SD. Using audiometric thresholds and word recognition in a treatment study. Otol Neurotol. 2006;27(1):110-6. 277. Thornton AR, Raffin MJ. Speech-discrimination scores modeled as a binomial variable. J Speech Hear Res. 1978;21(3):507-18. 278. Kramer S. Table 7-3 Criticial Difference Values for PB words based on the binomial distribution. In: Audiology Science to Practice, Second Edition. SanDiego, CA; Plural Publishing. 2014. 279. Committee on Hearing and Equilibrium guidelines for the evaluation of hearing preservation in acoustic neuroma (vestibular schwannoma). American Academy of Otolaryngology-Head and Neck Surgery Foundation, INC. Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery. 1995;113(3):179-80. 280. US Department of Health and Human Services NIoH, National Cancer Institute. . Common Terminology Criteria for Adverse Events (CTCAE) Version 4.03. evsncinihgov/ftp1/CTCAE/CTCAE_403_2010-06-14_QuickReference_5x7pdf Updated June 14, 2010 281. Chamberlain MC, Glantz MJ, Fadul CE. Recurrent meningioma: salvage therapy with long- acting somatostatin analogue. Neurology. 2007;69(10):969-73. 282. Farschtschi S, Kollmann P, Dalchow C, Stein A, Mautner VF. Reduced dosage of bevacizumab in treatment of vestibular schwannomas in patients with neurofibromatosis type 2. European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino- Laryngological Societies. 2015;272(12):3857-60. 283. Alanin MC, Klausen C, Caye-Thomasen P, Thomsen C, Fugleholm K, Poulsgaard L, et al. The effect of bevacizumab on vestibular schwannoma tumour size and hearing in patients with neurofibromatosis type 2. European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies. 2015;272(12):3627-33. 284. Li KL, Djoukhadar I, Zhu X, Zhao S, Lloyd S, McCabe M, et al. Vascular biomarkers derived from dynamic contrast-enhanced MRI predict response of vestibular schwannoma to antiangiogenic therapy in type 2 neurofibromatosis. Neuro-oncology. 2016;18(2):275-82. 285. Kollar A, Hewer E, Kellner-Weldon F, Ochsenbein A. Complete pain relief after bevacizumab in a patient with neurofibromatosis type 2. Acta oncologica. 2015;54(2):280-3. 286. Alanin MC, Klausen C, Caye-Thomasen P, Thomsen C, Fugleholm K, Poulsgaard L, et al. Effect of bevacizumab on intracranial meningiomas in patients with neurofibromatosis type 2 - a retrospective case series. The International journal of neuroscience. 2015:1-5. 287. Morris KA, Golding JF, Blesing C, Evans DG, Ferner RE, Foweraker K, et al. Toxicity profile of bevacizumab in the UK Neurofibromatosis type 2 cohort. Journal of neuro-oncology. 2016. 288. Slusarz KM, Merker VL, Muzikansky A, Francis SA, Plotkin SR. Long-term toxicity of bevacizumab therapy in neurofibromatosis 2 patients. Cancer chemotherapy and pharmacology. 2014;73(6):1197-204. 289. Kaus MR, Warfield SK, Nabavi A, Black PM, Jolesz FA, Kikinis R. Automated segmentation of MR images of brain tumors. Radiology. 2001;218(2):586-91. 290. Claus EB, Horlacher A, Hsu L, Schwartz RB, Dello-Iacono D, Talos F, et al. Survival rates in patients with low-grade glioma after intraoperative magnetic resonance image guidance. Cancer. 2005;103(6):1227-33. 291. Gering DT, Nabavi A, Kikinis R, Hata N, O'Donnell LJ, Grimson WE, et al. An integrated visualization system for surgical planning and guidance using image fusion and an open MR. Journal of magnetic resonance imaging : JMRI. 2001;13(6):967-75. 292. Henry JA, Bala A, Freeman SR, King AT, Rutherford SR, Mills S, et al. Bevacizumab: an effective treatment for spinal and peripheral nerve schwannomas associated with neurofibromatosis type II. . Submitted. 2012. 293. Morris KA, Afridi SK, Evans DG, Hensiek AE, McCabe MG, Kellett M, et al. The response of spinal cord ependymomas to bevacizumab in patients with neurofibromatosis Type 2. Journal of neurosurgery Spine. 2016:1-9.

212 294. Sughrue ME, Kane AJ, Kaur R, Barry JJ, Rutkowski MJ, Pitts LH, et al. A prospective study of hearing preservation in untreated vestibular schwannomas. Journal of neurosurgery. 2011;114(2):381-5. 295. Versleijen MW, Verbist BM, Mulder JJ, de Geus-Oei LF, van Herpen CM. Avastin scintigraphy in surveillance of bevacizumab treatment in a patient with neurofibromatosis type 2: a case report. Clinical nuclear medicine. 2014;39(3):277-80. 296. Jackson A, Li KL, Zhu X. Semi-quantitative parameter analysis of DCE-MRI revisited: monte- carlo simulation, clinical comparisons, and clinical validation of measurement errors in patients with type 2 neurofibromatosis. PloS one. 2014;9(3):e90300. 297. Ahlawat S, Fayad LM, Khan MS, Bredella MA, Harris GJ, Evans DG, et al. Current whole- body MRI applications in the neurofibromatoses: NF1, NF2, and schwannomatosis. Neurology. 2016;87(7 Suppl 1):S31-9. 298. Ruggieri M, Pratico AD, Evans DG. Diagnosis, Management, and New Therapeutic Options in Childhood Neurofibromatosis Type 2 and Related Forms. Seminars in pediatric neurology. 2015;22(4):240-58. 299. Lim SH, Ardern-Holmes S, McCowage G, de Souza P. Systemic therapy in neurofibromatosis type 2. Cancer treatment reviews. 2014;40(7):857-61. 300. Fisher MJ, Avery RA, Allen JC, Ardern-Holmes SL, Bilaniuk LT, Ferner RE, et al. Functional outcome measures for NF1-associated optic pathway glioma clinical trials. Neurology. 2013;81(21 Suppl 1):S15-24. 301. Hanemann CO, Blakeley JO, Nunes FP, Robertson K, Stemmer-Rachamimov A, Mautner V, et al. Current status and recommendations for biomarkers and biobanking in neurofibromatosis. Neurology. 2016;87(7 Suppl 1):S40-8. 302. Evans DG, Ramsden R, Huson SM, Harris R, Lye R, King TT. Type 2 neurofibromatosis: the need for supraregional care? The Journal of laryngology and otology. 1993;107(5):401-6. 303. Hexter A, Jones A, Joe H, Heap L, Smith MJ, Wallace AJ, et al. Clinical and molecular predictors of mortality in neurofibromatosis 2: a UK national analysis of 1192 patients. Journal of medical genetics. 2015;52(10):699-705.

213

Appendix 1 Neuroimaging of tumours in patients with Neurofibromatosis Type 1 and Type 2: Background and recommended protocols.

Dr Simone Ardern-Holmes Neurology / Neurogenetics Departments The Children’s Hospital at Westmead Westmead, Sydney

November 2010

214 Contents:

Introduction : The application of novel medical treatments in Neurofibromatosis Type 1 and Type 2

Background information Neurofibromatosis Type 1 – Plexiform Neurofibromas Neurofibromatosis Type 2 – Vestibular Schwannomas and Meningiomas

Neuroimaging in Neurofibromatosis Type 1 and Type 2

Recommended MRI protocols for tumours associated with Neurofibromatosis Type 1 and Type 2

References

215 Introduction: The application of novel medical treatments in Neurofibromatosis Type 1 and Type 2

Neurofibromatosis Type 1 (NF1) and Neurofibromatosis Type 2 (NF2) are distinct tumour-prone genetic disorders for which new treatment options are becoming available due to advances in the understanding of tumour biology and specifically the underlying molecular basis of these conditions [1-4]. Neuroimaging surveillance of tumours occurring in patients with NF1 and NF2 is central to following the progression of tumours, identifying which patients may benefit from novel treatments, and evaluating treatment response.

Your assistance with optimising tumour imaging for NF1 and NF2 patients in your area is very much appreciated.

Background Information

NF1 and NF2 are both autosomal dominant disorders, NF1 affecting about 1:3500 individuals and NF2 between 1:25,000 to 1:40,000 people. The gene for NF1 has been identified on chromosome 17 and encodes the protein neurofibromin. NF2 is caused by mutations in the gene on chromosome 22, which produces the protein variably named scwannomin or “merlin”. These proteins function as tumour suppressor, and as such, when mutations occur in the genes for NF1 and NF2 this tumour suppressor function is lost and patients are vulnerable to the formation of a range of tumours affecting primarily the nervous system, but also other parts of the body.

216

Neurofibromatosis Type 1: Plexiform Neurofibromas Some of the major medical complications of NF1 are due to plexiform neurofibromas (PNFs) which are usually diagnosed in children. Plexiform neurofibromas are externally obvious in approximately 25% of patients, and with increased use of MRI, it is now recognised that at least 40% of patients also have internal tumours [5]. These tumours can cause significant disfiguration and functional impairment depending on the location of the tumour and involvement of adjacent tissues, including pain, visual loss, limb weakness, and abdominal obstruction. There is a lifelong risk of malignant transformation [6] which carries a poor prognosis for five year survival. The imaging of plexiform neurofibromas is complex due to the potentially extensive, infiltrative nature of these tumours. Some of these tumours can be surgically removed, but unfortunately, regrowth is common.

Neurofibromatosis Type 2: Vestibular Schwannomas and Meningiomas Vestibular schwannomas are the most frequent tumours affecting 95% of all patients with NF2, causing tinnitus, vertigo, hearing loss, and risk of brain stem compression. About 20% of patients with NF2 present with symptoms before the age of 15 years, and of these, 43% have symptoms associated with vestibular schwannoma. Unfortunately, increased morbidity is associated with these tumours among individuals with NF2 compared with patients with sporadic vestibular schwannoma (in the absence of NF2). Furthermore, there is a significant risk of early mortality secondary to vestibular schwannoma in the NF2 population, estimated at up to 60% by the age of 44 years in one report. A range of other tumours including meningiomas, schwannomas, gliomas, and ependymomas are characteristic of NF2, and meningiomas are the next priority target for medical treatment in patients with NF2.

To date, surgery and radiosurgery have been first line treatment approaches. However, these treatments do not typically yield improvements in hearing loss secondary to vestibular tumours or other functional deficits such as visual loss due to

217 optic nerve sheath meningiomas. Furthermore, surgery and radiosurgery have other associated risks and side effects.

Effective alternative medical treatments for NF1 and NF2 associated tumours are becoming available and need to be carefully/critically assessed for safety and efficacy in this patient population [1, 7].

Neuroimaging in Neurofibromatosis Type 1 and 2

Following the symptomatic and radiographic progression of tumours in NF1 and NF2 patients is the essential backdrop against which novel medical therapies can be considered. In recent years, advances in neuroimaging have allowed better evaluation of tumour growth due to improvements in image acquisition and data analysis. It is now evident that 3 dimensional approaches provide a more sensitive assessment of tumour progression than 2 dimensional assessments [5, 8-10].

In the management of NF1/NF2 patients, it is our goal to ensure close surveillance of progressive tumours to provide critical baseline information regarding growth rates which can be used in the assessment of response to novel medical therapies. We hope to facilitate treatment of patients across Australia, in cooperation with neuroimaging and treatment facilities around the country.

In order to provide the best ongoing treatment options, the MR Imaging for each of these patients needs to be standardised so that volume measurements of the various lesions can be calculated.

It would be very much appreciated if all sites performing examinations on NF1 and NF2 patients could follow the protocols shown on pages 6 and 7 as closely as possible, with particular emphasis on ensuring that the entire lesion/s is covered and that the slices are acquired contiguously (with no gap). Acquisition of the data in this fashion will ensure the accuracy of subsequent volume measurements.

218 Recommended MRI protocols for tumours associated with Neurofibromatosis Type 1 and Type 2

The following guidelines are recommended to optimise assessment of NF1 and NF2 associated tumours:

Brain lesions Use your site's clinical pre-contrast protocol but with contiguous slices (no gap), including axial T1-W sequence Ensure all axial sequences cover entire brain so that no lesions are missed Post contrast in 2 planes (usually axial and coronal). Please cover brain entirely 5mm slice thickness should be sufficient unless lesions are very small No need for fat saturation if lesions are intracranial

Plexiform neurofibromas in body (including face) in NF1: Pre contrast axial and coronal T1-W Pre contrast axial and coronal T2-W FS OR STIR sequences Post contrast axial and coronal T1-W with fat saturation Contiguous 5-10mm slices (no gap) (depending on size of lesion: 5mm slices for smaller lesions, 10mm for larger lesions) Cover entire lesion in 2 planes to enable lesion volumes to be calculated.

Optional Whole-body STIR protocol for NF1(coronal plane). This protocol need only be run on patients who have multiple plexiform lesions involving the whole body.

The parameters are per station. Usually need 5 stations to cover head to ankles.

Slices 20 FOV: 500 mm Slice thickness: 10 mm (no gap)

219 TR: 4190 ms TE 113 ms TI: 150 ms Averages 2 Concatenations 2 Flip angle 150 ms Bandwidth 252 Resolution 320 x 240 Imaging time: 2:56 min

Optic meningioma and vestibular schwannoma in NF2:

Pre contrast axial T1-W sequence Pre contrast axial and coronal T2-W fat saturated sequences 2-3mm slice thickness (no gap) Lesion entirely covered in both planes

T1-W post contrast on both axial and coronal planes because: 1. very frequently, if two schwannomas are in very close proximity, it will not be easy to differentiate them in a single plane. 2. if images are suboptimal in one plane for any reason, the second plane becomes vital for volume calculation.

We hope you will find this a helpful resource and very much appreciate your efforts in catering for the specific requirements of our patients with NF1 and NF2.

We would appreciate receiving a copy of images acquired at your centre on a CD for detailed analysis.

220 Contact Us Given the complexity of volumetric analysis of tumours associated with NF1 and NF2, we are developing a team of dedicated radiographers, radiologists and image analysis specialists to assess these images.

Key Team Members are listed below with contact details.

Please don’t hesitate to contact us with any questions or queries.

Sheryl Foster Senior MRI Research Radiographer 9845 7206 Dr Lavier Gomes Neuroradiologist, Westmead Hospital 98456522 Dr Mayuresh Korgaonkar Senior Imaging Scientist, Brain Dynamics Centre 9845 817 Dr Simone Ardern-Holmes Paediatric Neurologist, 9845 1164 The Children’s Hospital at Westmead Natalie Gabrael, Clinical Trials Coordinator, 9845 1904 The Children’s Hospital at Westmead Dr Mark Wong Oncologist, Cancer Care Centre, 02 9845 9957 Westmead Hospital Professor Kathryn North Clinical Geneticist/Paediatric Neurologist, 9845 1903 Head, Institute of Neuroscience and Muscle Research, The Children’s Hospital at Westmead

221 References

1. Kissil, J.L., et al., What's new in neurofibromatosis? Proceedings from the 2009 NF Conference: new frontiers. Am J Med Genet A. 152A(2): p. 269-83. 2. McClatchey, A.I., Neurofibromatosis. Annu Rev Pathol, 2007. 2: p. 191-216. 3. Williams, V.C., et al., Neurofibromatosis type 1 revisited. Pediatrics, 2009. 123(1): p. 124-33. 4. Asthagiri, A.R., et al., Neurofibromatosis type 2. Lancet, 2009. 373(9679): p. 1974-86. 5. Mautner, V.F., et al., Assessment of benign tumor burden by whole-body MRI in patients with neurofibromatosis 1. Neuro Oncol, 2008. 10(4): p. 593-8. 6. Korf, B.R., Malignancy in neurofibromatosis type 1. Oncologist, 2000. 5(6): p. 477-85. 7. Plotkin, S.R., et al., Suggested response criteria for phase II antitumor drug studies for neurofibromatosis type 2 related vestibular schwannoma. J Neurooncol, 2009. 93(1): p. 61-77. 8. Harris, G.J., et al., Three-dimensional volumetrics for tracking vestibular schwannoma growth in neurofibromatosis type II. Neurosurgery, 2008. 62(6): p. 1314-9; discussion 1319-20. 9. Dombi, E., et al., NF1 plexiform neurofibroma growth rate by volumetric MRI: relationship to age and body weight. Neurology, 2007. 68(9): p. 643-7. 10. Cai, W., et al., Tumor burden in patients with neurofibromatosis types 1 and 2 and schwannomatosis: determination on whole-body MR images. Radiology, 2009. 250(3): p. 665-73.

222 Appendix 2. Additional protocol patient selection, treatment and adverse monitoring details for imatinib treatment of plexiform neurofibromas in patients with NF1.

Eligibility criteria (to minimize risk of adverse events): Hepatic function: Participants must have adequate liver function defined as bilirubin (sum of conjugated + unconjugated) ≤2x upper limit of normal for age, and AST and ALT ≤3 x upper limit of normal for age; Renal function: Participants must have adequate renal function defined as serum creatinine ≤1.5x upper limits of normal for age, or a creatinine clearance of greater than 70 ml/m/1.73m2; Haematologic function: Participants must have an absolute neutrophil count of greater than 1,000, a haemoglobin of greater than 9 g/dl, and a platelet count of greater than 100,000.

Discontinuation of medication: A participant may be taken off imatinib for the following reasons: • The development of significant drug toxicity, such as recurrent grade 3 or 4 toxicity after dose reduction; and/or persistent grade >2 toxicity for >X days without administration of the drug (see adverse event monitoring below); • Treatment failure: ≥20% increase in 3D tumour volume; • Serious non-compliance as determined by the research team; • The participant refuses further treatments and/or wishes to withdraw from the study; • The development of a concurrent serious medical condition that might preclude or contraindicate the administration of imatinib; • It is deemed in the best interest of the participant to stop the study by the research team.

223

Adverse Events and Relationship to Imatinib Administration: • Adverse Event – Any unfavourable and unintended sign (including an abnormal laboratory finding), symptom or disease regardless of whether it is considered related to the study medications (attribution of unrelated, unlikely, possible, probable, or definite).

Participants who experience grade 2 toxicity related to imatinib will have the medication withheld until the toxicity resolves (grade <1), and then restarted at the same dose level. If grade 2 toxicity recurs, the dose will be withheld again until the toxicity resolves (grade <1) and then reduced to 50% of the dose. If grade 2 toxicity recurs, medication will be ceased.

Participants who experience grade 3 or 4 toxicity related to imatinib will have the dose withheld. If the toxicity returns to grade <1 within 10 days, the participant may resume imatinib at a reduced dose. If the toxicity persists at grade >2 for >10 days without administration of imatinib or the grade 3 or 4 toxicity recurs at the lower dose, medication will be ceased.

Treatment will be ceased in the event of any significant adverse event (Grade 4/5). In the event of milder adverse events, consideration will be given to temporary cessation and/or decreasing the treatment dose.

224

Appendix 3 Name: ______

Date: ______

NF1 Symptoms Questionnaire

Headache:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Dizziness:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Falls:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Fatigue:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Weakness in Legs:

Left Leg:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Right Leg:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

225

Paraesthesia: Pins/Needles:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Numbness:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Back Pain:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Neck Pain:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Speech:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Swallowing:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Incontinence: Bladder: Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5 Bowel: Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

226

Constipation:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Vision: Blurry:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Double vision:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Nausea:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Vomiting:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Other: (please describe) ______

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Linear overall well-being scale (please indicate by placing an “X” on the line):

I I

[Low] [High]

227 Appendix 4. Medical Outcomes Study 36-Item Short Form (SF36) questionnaire.

SF-36 QUESTIONNAIRE ( 1992 -- Medical Outcomes Trust)

Patient Name: ______Date: ______

1. In general, would you say your health is: (circle one)

Excellent Very good Good Fair Poor

2. Compared to one year ago, how would you rate your health in general now? (circle one)

Much better now than one year ago.

Somewhat better now than one year ago.

About the same as one year ago.

Somewhat worse than one year ago.

Much worse than one year ago.

3. The following items are about activities you might do during a typical day. Does your health now limit you in these activities? If so, how much? (Mark each answer with an X)

Yes, Yes, No, Not ACTIVITIES Limited Limited Limited A Lot A Little At All a. Vigorous activities, such as running, lifting heavy objects, participating in strenuous sports b. Moderate activities, such as moving a table, pushing a vacuum cleaner, bowling, or playing golf c. Lifting or carrying groceries

d. Climbing several flights of stairs

e. Climbing one flight of stairs

f. Bending, kneeling or stooping

g. Walking more than a mile

h. Walking several blocks

i. Walking one block

j. Bathing or dressing yourself

228 4. During the past 4 weeks, have you had any of the following problems with your work or other regular daily activities as a result of your physical health? (Mark each answer with an X)

YES NO a. Cut down on the amount of time you spent on work or other activites b. Accomplished less than you would like c. Were limited in the kind of work or other activities d. Had difficulty performing the work or other activities (for example, it took extra effort)

5. During the past 4 weeks, have you had any of the following problems with your work or other regular daily activities as a result of any emotional problems (such as feeling depressed or anxious)? (Mark each answer with an X)

YES NO a. Cut down the amount of time you spent on work or other activities b. Accomplished less than you would like c. Didn’t do work or other activities as carefully as usual

6. During the past 4 weeks, to what extent has your physical health or emotional problems interfered with your normal social activities with family, friends, neighbors or groups? (circle one)

Not at all Slightly Moderately Quite a bit Extremely

7. How much bodily pain have you had during the past 4 weeks? (circle one)

None Very mild Mild Moderate Severe Very severe

8. During the past 4 weeks, how much did pain interfere with your normal work (including both work outside the home and housework)?

Not at all A little bit Moderately Quite a bit Extremely

229 9. These questions are about how you feel and how things have been with you during the past 4 weeks. For each question, please give the one answer that comes closest to the way you have been feeling. How much of the time during the past 4 weeks – (Mark each answer with an X)

All of the Most of A Good Some of A Little None of Time the Time Bit of the the Time of the the Time Time Time a. Did you feel full of pep? b. Have you been a very nervous person? c. Have you felt so down in the dumps that nothing could cheer you up? d. Have you felt calm and peaceful? e. Did you have a lot of energy? f. Have you felt downhearted and blue? g. Did you feel worn out? h. Have you been a happy person? i. Did you feel tired?

10. During the past 4 weeks, how much of the time has your physical health or emotional problems interfered with your social activities (like visiting with friends, relatives, etc.)? (circle one)

All of the time Most of the time Some of the time A little of the time None of the time

11. How TRUE or FALSE is each of the following statements for you?

Definitely Mostly Don’t Mostly Definitely True True Know False False a. I seem to get sick a little easier than other people b. I am as healthy as anybody I know c. I expect my health to get worse d. My health is excellent

230

Appendix 5. Adverse effects/toxicity of imatinib.

Common Occasional Rare Happens to 21-100 Happens to 5-20 Happens to <5 children children out of every children out of out of every 100 100 every 100

Immediate: Dyspepsia/heartburn, Fever, liver Brain swelling, Within 1-2 days of nausea/vomiting, dysfunction, inflammation of the bone, receiving drug headache, swelling in abdominal pain and Inflammation of the lungs limbs, face, periorbital cramping, muscle area, weight gain and joint aches and pains Prompt: Low blood counts Decreased bone GI bleeding, diarrhoea, Within 2-3 weeks, predisposing to marrow cellularity, swallowing difficulties, prior to the next anaemia, infection, or skin rash, muscle esophagitis, pain while course bleeding, pain and cramping, swallowing, severe skin fatigue anorexia rash, bleeding associated with low platelets

Delayed: Growth restriction may Pigmentation Liver dysfunction Any time later occur in children changes (associated with during therapy, (hypo-, vitiligo) coincident excluding the acetaminophen use) above conditions

231

Appendix 6. Name: ______

Date: ______

NF2 Symptoms Questionnaire

Headache:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Dizziness:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Tinnitus:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Falls:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Fatigue:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Weakness in Legs:

Left Leg:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Right Leg:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

232

Paraesthesia: Pins/Needles:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Numbness:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Back Pain:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Neck Pain:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Speech:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Swallowing:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Incontinence: Bladder:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Bowel:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

233

Constipation:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Vision: Blurry:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Double vision:

N/A Never Less often than monthly Monthly Weekly Daily Many times a day

X 0 1 2 3 4 5

Nausea:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Vomiting:

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Other: (please describe) ______

Never Less often than monthly Monthly Weekly Daily Many times a day

0 1 2 3 4 5

Linear overall well-being scale (please indicate by placing an “X” on the line):

I I

[Low]

234 Appendix 7. Speech, Spatial and Qualities of Hearing Scale.

235 Speech Spatial Qualities

Advice about answering the questions

The following questions inquire about aspects of your Please answer the following questions, then go ability and experience hearing and listening in on to the questions about your hearing different situations.

For each question, put a mark, such as a cross (x), Your name : anywhere on the scale shown against each question that runs from 0 through to 10. Putting a mark at 10 Today’s date : means that you would be perfectly able to do or experience what is described in the question. Putting Your age: a mark at 0 means you would be quite unable to do or experience what is described. Please check one of these options:

As an example, question 1 asks about having a I have no hearing aid/s conversation with someone while the TV is on at the same time. If you are well able to do this then put a I use one hearing aid (left ear ) mark up toward the right-hand end of the scale. If I use one hearing aid (right ear) you could follow about half the conversation in this situation put the mark around the mid-point, and so I use two hearing aids (both ears) on. If you have been using hearing aid/s, for how long? We expect that all the questions are relevant to your everyday experience, but if a question ______years describes a situation that does not apply to you, put a cross in the “not applicable” box. Please also ______months write a note next to that question explaining why it does not apply in your case. or If you have two aids and have used them for _____ weeks different lengths of time, please write down both.

SSQ 5.6 page 1 Speech Spatial Qualities (Part 1: Speech hearing)

1. You are talking with one other person and there is a TV on in the Not at all Perfectly same room. Without turning the TV down, can you follow what the 0 1 2 3 4 5 6 7 8 9 10 Not applicable person you’re talking to says?

2. You are talking with one other person in a quiet, carpeted lounge- Not at all Perfectly room. Can you follow what the other person says? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

3. You are in a group of about five people, sitting round a table. It is Not at all Perfectly an otherwise quiet place. You can see everyone else in the group. 0 1 2 3 4 5 6 7 8 9 10 Not applicable Can you follow the conversation?

4. You are in a group of about five people in a busy restaurant. You Not at all Perfectly can see everyone else in the group. Can you follow the 0 1 2 3 4 5 6 7 8 9 10 Not applicable conversation?

5. You are talking with one other person. There is continuous Not at all Perfectly background noise, such as a fan or running water. Can you follow 0 1 2 3 4 5 6 7 8 9 10 Not applicable what the person says?

SSQ 5.6 page 2 Speech Spatial Qualities (Part 1: Speech hearing, continued)

6. You are in a group of about five people in a busy restaurant. You Not at all Perfectly CANNOT see everyone else in the group. Can you follow the 0 1 2 3 4 5 6 7 8 9 10 Not applicable conversation?

7. You are talking to someone in a place where there are a lot of Not at all Perfectly echoes, such as a church or railway terminus building. Can 0 1 2 3 4 5 6 7 8 9 10 you follow what the other person Not applicable says?

8. Can you have a conversation with someone when another person is Not at all Perfectly speaking whose voice is the same pitch as the person you’re talking 0 1 2 3 4 5 6 7 8 9 10 Not applicable to?

9. Can you have a conversation with someone when another person is Not at all Perfectly speaking whose voice is different in pitch from the person you’re 0 1 2 3 4 5 6 7 8 9 10 Not applicable talking to?

10. You are listening to someone talking to you, while at the same Not at all Perfectly time trying to follow the news on TV. Can you follow what both 0 1 2 3 4 5 6 7 8 9 10 Not applicable people are saying?

SSQ 5.6 page 3 Speech Spatial Qualities (Part 1: Speech hearing, continued)

11. You are in conversation with one person in a room where there are Not at all Perfectly many other people talking. Can you follow what the person you 0 1 2 3 4 5 6 7 8 9 10 Not applicable are talking to is saying?

12. You are with a group and the conversation switches from one Not at all Perfectly person to another. Can you easily follow the conversation without 0 1 2 3 4 5 6 7 8 9 10 missing the start of what each new Not applicable speaker is saying?

13. Can you easily have a conversation on the telephone? Not at all Perfectly

0 1 2 3 4 5 6 7 8 9 10 Not applicable

14. You are listening to someone on the telephone and someone next to Not at all Perfectly you starts talking. Can you follow what’s being said by both 0 1 2 3 4 5 6 7 8 9 10 Not applicable speakers?

SSQ 5.6 page 4 Speech Spatial Qualities (Part 2: Spatial hearing)

1. You are outdoors in an unfamiliar place. You hear someone using a Not at all Perfectly lawnmower. You can’t see where they are. Can you tell right away 0 1 2 3 4 5 6 7 8 9 10 Not applicable where the sound is coming from?

2. You are sitting around a table or at a meeting with several people. Not at all Perfectly You can’t see everyone. Can you tell where any person is as soon as 0 1 2 3 4 5 6 7 8 9 10 Not applicable they start speaking?

3. You are sitting in between two people. One of them starts to Not at all Perfectly speak. Can you tell right away whether it is the person on your 0 1 2 3 4 5 6 7 8 9 10 left or your right, without having Not applicable to look? 4. You are in an unfamiliar house. It is quiet. You hear a door slam. Not at all Perfectly Can you tell right away where that sound came from? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

5. You are in the stairwell of a building with floors above and Not at all Perfectly below you. You can hear sounds from another floor. Can you 0 1 2 3 4 5 6 7 8 9 10 Not applicable readily tell where the sound is coming from?

SSQ 5.6 page 5 Speech Spatial Qualities (Part 2: Spatial hearing, continued)

6. You are outside. A dog barks loudly. Can you tell immediately Not at all Perfectly where it is, without having to look? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

7. You are standing on the footpath of a busy street. Can you hear Not at all Perfectly right away which direction a bus or truck is coming from before 0 1 2 3 4 5 6 7 8 9 10 Not applicable you see it?

8. In the street, can you tell how far away someone is, from the sound Not at all Perfectly of their voice or footsteps? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

9. Can you tell how far away a bus or a truck is, from the sound? Not at all Perfectly

0 1 2 3 4 5 6 7 8 9 10 Not applicable

10. Can you tell from the sound which direction a bus or truck is moving, Not at all Perfectly for example, from your left to your right or right to left? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

SSQ 5.6 page 6 Speech Spatial Qualities (Part 2: Spatial hearing, continued)

11. Can you tell from the sound of their voice or footsteps which Not at all Perfectly direction a person is moving, for example, from your left to your 0 1 2 3 4 5 6 7 8 9 10 Not applicable right or right to left?

12. Can you tell from their voice or footsteps whether the person is Not at all Perfectly coming towards you or going away? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

13. Can you tell from the sound whether a bus or truck is coming Not at all Perfectly towards you or going away? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

14. Do the sounds of things you are able to hear seem to be inside your Inside my head Out there head rather than out there in the world? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

15. Do the sounds of people or things you hear, but cannot see at first, Much closer Not closer turn out to be closer than expected when you do see them? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

SSQ 5.6 page 7 Speech Spatial Qualities (Part 2: Spatial hearing, continued)

16. Do the sounds of people or things you hear, but cannot see at first, Much further Not further turn out to be further away than expected when you do see them? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

17. Do you have the impression of sounds being exactly where you Not at all Perfectly would expect them to be? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

SSQ 5.6 page 8 Speech Spatial Qualities (Part 3: Qualities of hearing)

1. Think of when you hear two things at once, for example, water Not at all Perfectly running into a basin and, at the same time, a radio playing. Do 0 1 2 3 4 5 6 7 8 9 10 you have the impression of these Not applicable as sounding separate from each other?

2. When you hear more than one sound at a time, do you have the Jumbled Not jumbled impression that it seems like a single jumbled sound? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

3. You are in a room and there is music on the radio. Someone else Not at all Perfectly in the room is talking. Can you hear the voice as something 0 1 2 3 4 5 6 7 8 9 10 Not applicable separate from the music?

4. Do you find it easy to recognise different people you know by the Not at all Perfectly sound of each one’s voice? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

5. Do you find it easy to distinguish different pieces of music that you Not at all Perfectly are familiar with? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

SSQ 5.6 page 9 Speech Spatial Qualities (Part 3: Qualities of hearing, continued)

6. Can you tell the difference between different sounds, for Not at all Perfectly example, a car versus a bus; water boiling in a pot versus food 0 1 2 3 4 5 6 7 8 9 10 Not applicable cooking in a frypan?

7. When you listen to music, can you make out which instruments are Not at all Perfectly playing? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

8. When you listen to music, does it sound clear and natural? Not at all Perfectly

0 1 2 3 4 5 6 7 8 9 10 Not applicable

9. Do everyday sounds that you can hear easily seem clear to you (not Not at all Perfectly blurred)? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

10. Do other people’s voices sound clear and natural? Not at all Perfectly

0 1 2 3 4 5 6 7 8 9 10 Not applicable

SSQ 5.6 page 10 Speech Spatial Qualities (Part 3: Qualities of hearing, continued)

11. Do everyday sounds that you hear seem to have an artificial or Unnatural Natural unnatural quality? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

12. Does your own voice sound natural to you? Not at all Perfectly

0 1 2 3 4 5 6 7 8 9 10 Not applicable

13. Can you easily judge another person’s mood from the sound of Not at all Perfectly their voice? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

14. Do you have to concentrate very much when listening to someone Concentrate hard Not need to concentrate or something? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

15. Do you have to put in a lot of effort to hear what is being said in Lots of effort No effort conversation with others? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

SSQ 5.6 page 11 Speech Spatial Qualities (Part 3: Qualities of hearing, continued)

16. When you are the driver in a car can you easily hear what someone Not at all Perfectly is saying who is sitting alongside you? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

17. When you are a passenger can you easily hear what the driver is Not at all Perfectly saying sitting alongside you? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

18. Can you easily ignore other sounds when trying to listen to Not easily ignore Easily ignore something? 0 1 2 3 4 5 6 7 8 9 10 Not applicable

SSQ 5.6 page 12 Appendix 8. Adverse effects/toxicity of bevacizumab.

Common Occasional Rare 21-100/100 5-20/100 <5/100

Immediate: Asthenia, Dyspepsia, fever, chest, Infusion reactions, Within 1-2 days hypertension, back and abdominal flatulence, dry mouth, of first dose Nausea, vomiting, pain, dizziness, rhinitis altered taste, tearing, anorexia, diarrhoea, rash, drowsiness, acidosis constipation, cough, pruritus, headache, dyspnoea Prompt: Epistaxis, Stomatitis, URI, GI Thrombotic/ Within 2-3 weeks proteinuria, haemorrhage, GI ulcer, thromboembolic events, infection, myalgia, alopecia, weight loss, exfoliative dermatitis, skin arthralgia, sinusitis, cytopenias, voice ulcer, ↑ AST/ALT, ↑ neutropenia change, depression, UTI, creatinine, Haemorrhage, fever colitis, GI perforation*, GI obstruction, Hypokalaemia, Hyper- bilirubinaemia, Thrombocytopenia, Hyperaesthesia, paraesthesia, infection, leukoencephalopathy, Delayed: Nasal-septal perforation Wound dehiscence, CHF, Any time later nephrotic syndrome, TOF during therapy with chemo and radiation of oesophagus/ trachea, renal failure Unknown Teratogenicity in rabbits (doses two-fold greater than recommended human Frequency and dose on a mg/kg basis; decreases in maternal and foetal body weights, Timing increased rate foetal resorption, increased specific gross and skeletal foetal alterations.

*Toxicity may also occur later; CHF=congestive heart failure, TOF=trachea-esophageal fistula, UTI=urinary tract infection.

236 Appendix 9. Bevacizumab funding details

Funding Source Comment on funding (Number of patients) Public Health Sector Ongoing during paediatric care (1); Funding withdrawn (6) due to static tumour volume, despite improved hearing (1); withdrawn due to variable compliance with follow up (1); withdrawn following treatment response, then restarted after disease progression off treatment (1); withdrawn after positive response to therapy at 26months due to insufficient funds, followed by surgical treatment (1); commenced after self-funding demonstrated significant benefit (1) Self-funded Duration 6-12 months; 2 following withdrawal of public (3) funding; one at commencement of treatment, followed by public funding upon demonstrated benefit Private Health Insurer One from commencement; one following demonstrated (2) benefit

237 Appendix 10. Published Papers

238 Current Treatment Options in Neurology DOI 10.1007/s11940-011-0142-9

Pediatric Neurology (Harvey Singer, Section Editor)

Therapeutics for Childhood Neurofibromatosis Type 1 and Type 2 Simone L. Ardern-Holmes, MBChB, FRACP1 Kathryn N. North, FRACP, MD2,*

Address 1TY Nelson Department of Neurology and Neurosurgery, The Children’s Hospital at Westmead, Corner Hawkesbury Rd and Hainsworth Avenue, Westmead, NSW 2145, Australia Email: [email protected] *,2Institute for Neuroscience and Muscle Research, The Children’s Hospital at Westmead, Corner Hawkesbury Rd and Hainsworth Avenue, Westmead, NSW 2145, Australia Email: [email protected]

* Springer Science+Business Media, LLC 2011

Opinion statement Neurofibromatosis type 1 (NF1) and type 2 (NF2) are genetically and medically distinct neurocutaneous disorders that are both associated with tumors affecting the central and peripheral nervous systems. NF1 has a frequency of 1 in 3,000, compared with 1 in 30,000 for NF2. Careful surveillance is important for both conditions, to allow early identification and treatment of complications. The most common and important problems in NF1 are cognitive impairment, optic pathway gliomas, plexiform neurofibromas, and orthopaedic issues. Early intervention and tailored educational programs are indicated for learning difficulties. Attention deficit hyperactivity disorder may be amenable to treatment with stimulant medication. A clinical trial is under way to evaluate lovastatin in the treatment of cognitive problems in children with NF1. Chemotherapy with vincristine and carboplatin is the current standard of care for symptomatic optic pathway gliomas, but new agents with improved efficacy are needed. Plexiform neurofibromas may be treated with surgery, but often recur. To date, no medical therapy has proven effective in limiting plexiform neurofibroma growth, but several candidate medications are under consideration in clinical trials. Malignant peripheral nerve sheath tumors may arise in preexisting plexiform neurofibromas, so changes in tumor growth or an increase in pain or focal neurologic deficit should prompt further investigation and early treatment with wide surgical resection, with or without adjuvant chemotherapy or radiotherapy. Specialist surgical intervention may be needed for scoliosis and tibial pseudoarthrosis. In NF2, surgical treatment remains a cornerstone of management for symptomatic progressive vestibular schwannomas, meningiomas, and spinal tumors. Vascular endothelial growth factor inhibitors show promise for the treatment of vestibular schwannomas, with the aim of delaying surgery, and other targeted molecular therapies are becoming available as investigational options. Hearing aids Pediatric Neurology (Harvey Singer, Section Editor)

and brainstem and cochlear implants havearoleinoptimizingfunctionalhearing in some patients. Specialist ophthalmology input should be arranged to monitor for ophthalmologic complications. A coordinated effort is needed to enroll NF1 and NF2 patients in international multicenter clinical trials of promising new pharmacologic agents. Genetic testing is useful for prenatal diagnosis and may be important in understanding individual responses to novel medical therapies in the future. Effec- tive transition to adult services is important, considering the likelihood of further complications in the adult years.

Introduction Neurofibromatosis types 1 and 2 (NF1 and NF2) are dis- childhood. Patients with both disorders require regular tinct genetic disorders that are both characterized by cu- disease surveillance throughout life and a multidis- taneous manifestations and benign tumors of the central ciplinary management approach. To date, effective and peripheral nervous system. NF1 has a frequency of 1 medical treatment has been limited, but recent in 3,000, and most patients present during childhood advances in our understanding of molecular patho- with multiple café au lait spots and skinfold freckling. genesis has led to a range of molecularly targeted NF2 has a frequency of 1 in 30,000 and less obvious cu- medications that are becoming available for investi- taneous features; the hallmark of NF2 is vestibular gational use. schwannomas, and only 20% of patients present in

Neurofibromatosis type 1

Neurofibromatosis type 1 is caused by mutations in the large NF1 gene located on chromosome 17q11.2, encoding the protein neurofibromin. Neuro- fibromin is known to act as a tumor suppressor via Ras-GTPase activation, which causes down-regulation of cellular signalling by the Ras/mitogen-activated protein kinase (MAPK) pathway. In individuals with NF1 and nonfunctional neurofibromin, Ras signalling is increased, promoting cellular growth, proliferation, and differentiation leading to tumor formation and other manifestations of disease, including deficits in hippocampal learning [1, 2]. Neurofibromin is likely to have additional functions; for example, loss of normal GABA-mediated inhibition has recently been shown to contribute to corticostriatal dysfunction associated with working memory deficits in NF1 [3].

Diagnosis Clinical diagnostic criteria for NF1 were established in 1987 and are satisfied when two of the following conditions are met [4•]: & Café au lait macules (six or more larger than 5 mm before puberty or 15 mm after puberty) & Skin-fold freckling (axillae, groin, neck) & Two or more iris Lisch nodules & Characteristic skeletal dysplasia (tibial dysplasia, sphenoid wing dysplasia) Therapies for Childhood Neurofibromatosis Ardern-Holmes and North

& Optic pathway glioma & Two or more neurofibromas or one or more plexiform neurofibromas & Presence of a positive family history of NF1 affecting a first-degree relative. Young children typically present with multiple café au lait macules in isolation, with other signs of NF1 occurring over time [5, 6]. Macrocephaly affects about 45% of children and progressive head growth may occur over the first 1 or 2years.Alowthresholdforneuroimaging is appropriate, given an increased incidence of intracranial tumors. However, surveillance imaging in the absence of focal neurologic deficit or signs of increased intracranial pressure is not recommended. Optic pathway gliomas are more common in children less than 8 years of age and can occur during infancy. Plexiform neurofibromas are mostly present from birth and become more obvious over the first few years of life. Skin-fold freckling is typically seen from about 3 years of age, whereas Lisch nodules may appear in middle childhood and cutaneous neurofibromas more frequently occur in adolescence and adulthood.

Complications A recommended surveillance and treatment approach for important complications is shown in Table 1. The most frequent neurologic complication in childhood is cognitive dysfunction [7]. There is a “shift to the left” in intellectual functioning: the mean IQ for patients with NF1 is in the low 90s, and intellectual impairment (IQ G70) occurs in about 6% of patients. Academic learning difficulties are common in NF1: about 50% of children with NF1 perform poorly on tasks of reading, spelling, and mathematics, and specific learning disabilities (as defined by IQ–achievement discrepancies) are present in 20% of patients. Between 38% and 49% of children with NF1 fulfil the diagnostic criteria for attention deficit-hyperactivity disorder (ADHD) [7, 8]. Careful screening, supportive measures in pre-academic environments, and individually tailored educational programs are thus needed. The neurobiologic basis of cognitive dysfunction and learning disabilities in NF1 is not fully understood, although increased total brain volume and corpus callosum volume, cerebral asymmetries, and differences in grey and white matter have been described in affected individuals. Though T2 hyperintensities are commonly seen in childhood, these decrease with increasing age and are of uncertain significance. However, the presence of discrete thalamic T2 hyperintensities has been associated with severe and generalized cognitive dysfunction [9]. Speech and language disorders have been estimated to affect 18% to 58% of school-aged children and adolescents with NF1 [7, 10] and 68% of preschoolers [11]. Children with NF1 often have mild generalized hypotonia in association with less well-developed gross motor skills than their unaffected peers, causing minimal functional impairment. ADHD in the NF1 population is amenable to treatment with stimulant medication (as in other children with ADHD), although data on efficacy are limited [8]. Studies of cognitive functioning in the NF1 mouse model have suggested that attention and visual spatial learning deficits (hippocampal-based learning) are due to Ras activation. The cholesterol-lowering agent lovastatin, which inhibits GTPases including Ras, reverses these deficits in the NF1 mouse model [12], and trials of lovastatin in children with NF1 are currently under way. Pediatric Neurology (Harvey Singer, Section Editor)

Table 1. Current surveillance and treatment of the major medical complications associated with neurofibromatosis type 1 Complications Surveillance Treatment Cognitive impairment Developmental screening during Early intervention preschool years ADHD Screening at intervals during childhood Stimulant medication (e.g., at school entry) Learning difficulties Psychologist assessment during early Individually tailored educational support; school years (baseline) and when specific candidate for medication in clinical trial learning difficulty identified Speech/language disorder Speech evaluation Speech therapy Optic pathway glioma (OPG) Annual ophthalmology evaluation until – 8 years of age, every 2 years ages 8–18; cranial MRI for suspected OPG. For known OPG, quarterly ophthalmology Chemotherapy using vincristine and evaluation for 1 year, every 6 months for carboplatin if clinically indicated for 1 year, then annually until 8 years of age; symptomatic or progressing tumor if older than 8 years, for 3 further years Plexiform neurofibroma Annual clinical examination to identify Surgical debulking for progressive, and monitor growth; MRI every symptomatic tumors; candidate for 6–12 months for progressive lesions medication in clinical trial; analgesia when indicated Malignant peripheral nerve Urgent clinical examination for increasing Wide surgical excision; consider sheath tumor plexiform neurofibroma size, pain, or chemotherapy and radiotherapy; neurologic dysfunction; MRI, PET, biopsy candidate for medication of affected body region in clinical trial Tibial pseudoarthrosis Annual clinical evaluation (infants); Referral to experienced orthopaedic x-ray in the event of limb deformity surgeon; bracing, surgical intervention, and/or bisphosphonates Scoliosis Annual clinical evaluation throughout Referral to experienced orthopaedic childhood; x-ray in the event of abnormal surgeon; surgical intervention if spinal curvature clinically indicated Hypertension Annual blood pressure monitoring; For Renal physician referral known hypertension, urinary catecholamines, renal ultrasound with Doppler studies Heart murmur Careful annual examination Echocardiogram; referral to cardiologist Anxiety/mood disorder Annual clinical evaluation Referral to psychologist or psychiatrist

ADHD attention deficit hyperactivity disorder

Optic pathway glioma (OPG) affects 15% to 20% of children with NF1 [13], most before 8 years of age, with about half becoming symptomatic [14]. Symp- toms and signs include strabismus, proptosis, visual impairment, optic disk pallor, and precious puberty. Current surveillance recommendations are for an annual general examination to monitor growth and pubertal status and an annual ophthalmologic evaluation up to the age of 8 years, followed by an examination every 2 years until 18 years of age [13]. All children with a suspected diagnosis of OPG should undergo cranial MRI. From the time of diagnosis, monitoring to detect progressive disease rests with regular skilled pediatric ophthalmology assessment to- Therapies for Childhood Neurofibromatosis Ardern-Holmes and North gether with repeat MRIs. Ophthalmology evaluations are recommended every 3 months for the first year, followed by assessments every 6 months for 2 years, and then annual assessments. Optimal intervals for MRI surveillance have not yet been established, and different centers screen at intervals between 3 and 6 months in the first year. Ocular coherence tomography measures retinal nerve fibre layer thickness, which may be helpful as an adjunctive measurement for assessing progression in the future [15, Class IV]. Primary treatment for OPG is with chemotherapy, usually a combination of vincristine and carboplatin. There are no definitive evidence-based criteria to guide decisions about commencing chemotherapy. A retrospective multicenter study of 10 major international NF1 centers recently reviewed indications for commencing chemotherapy, demonstrating practice variation among institutions and visual deterioration in 29% of treated children [16, Class IV]. Prospective studies using novel agents are needed. Other intracranial tumors (typically low-grade gliomas) are less common and tend to have a more favorable prognosis than in non-NF1 patients [17]. Cutaneous and subcutaneous neurofibromas can itch and cause localized discomfort. The significant cosmetic deformity attendant on multiple lesions typically occurs in adulthood; surgical removal is currently the only treatment option. Plexiform neurofibromas are more complex lesions, thought to be congenital [18]. A recent MRI surveillance study identified plexiform neurofibromas in 57% of 65 children aged between 1.7 and 17.6 years, similar to estimates in adults. Of the children with plexiform neurofibromas, 46% experienced pain or neurologic or motor difficulties, usually associated with larger tumors [19]. Symptoms associated with tracheal compression may be life-threatening. The treatment of complicated plexiform neurofibromas remains a challenge. Symptomatic lesions may be amenable to surgical debulking, but complete resection may not be possible because of the invasive nature of these tumors, and regrowth is common. The goal of surveillance is to identify and treat actively growing symptomatic lesions during early childhood to limit disease progression. Three-dimensional MRI has been shown to be more sensitive than two-dimensional measurements for assessing growth, but it is not available in all centers [20]. A range of novel molecularly targeted agents, including inhibitors of the c-kit receptor such as imatinib [21], are currently being investigated. Patients with NF1, particularly those with a high plexiform neurofibroma tumor burden, have a significantly increased risk of malignant peripheral nerve sheath tumor (MPNST), with a lifetime risk of 8% to 13% [22]; this represents the major threat of early mortality. Whole-body MRI surveillance during childhood may help to stratify patients into two groups: those requiring infrequent ongoing scanning and those at risk of complications from existing plexiform neurofibromas, including the risk of transformation to MPNST. How- ever, there is currently a paucity of evidence regarding the utility of MR surveillance in children with asymptomatic lesions. Prospective studies are needed to evaluate the effectiveness of such surveillance. A rapid increase in plexiform neurofibroma growth, increasing pain, and new focal neurologic deficits or other regional symptoms and signs should prompt investigation with MRI [23] and 18F-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography PET/ CT studies to detect increased glucose metabolism [24, Class IV]. MPNST confirmed on biopsy is treated with wide surgical excision and adjuvant therapy. Re- Pediatric Neurology (Harvey Singer, Section Editor)

currence risk and metastatic potential are high, with median survival of 30.5 months across all ages and 20 months for children 1 to 17 years of age [25]. Low response rates to chemotherapy and radiation therapy for MPNST have focused efforts on the development of novel medical therapy and carefully coordinated clinical trials to improve patient outcomes. NF1 is associated with vasculopathy affecting multiple sites, including abdominal, renal, spinal, and intracranial vessels, with various consequences. The best-recognized manifestation of NF1 vasculopathy is hypertension secondary to renal artery stenosis. Blood pressure should be monitored at least annually, and hypertension should be investigated by renal artery ultrasound/Doppler, with surgical or dilation therapy to treat stenotic lesions. Most cases of hypertension in NF1 are essential hypertension and respond to medical management. Phaeochromocytoma is a very rare complication of NF1 but should be screened for in patients with elevated blood pressure. Cerebral vasculopathy affects 2% to 5% of children; 30% of these cases present with symptoms associated with ischaemia, but the others are diagnosed incidentally. Aspirin is recommended for patients with evidence of vasculopathy on neuroimaging [26,ClassIV]. Epilepsy occurs at an increased frequency in patients with NF1, affecting 3.8% to 7% of children, often in association with cerebral tumors and cortical malformations. In a series of 14 cases, 29% were drug-resistant [27]. A recent report documented infantile spasms in 0.76% of NF1 patients, compared with 0.02% to 0.05% in the general population [28]. Headache is common in NF1, affecting about 20% of patients. Most headaches are not associated with intracranial lesions, but MRI should be performed in patients with severe or recurrent headaches or features suggestive of increased intracranial pressure. Orthopaedic complications of NF1 during childhood include scoliosis and tibial pseudoarthrosis, which may require operative management. Scoliosis occurs in about 20% of patients with NF1, but only about 5% require surgical intervention; more severe scoliosis tends to present earlier (at 5–10 years of age) and is often associated with vertebral dysplasia or bony lesions due to an adjacent plexiform neurofibroma. Bony defects of the tibia or other long bones are congenital and usually present with bowing or fracture on weight bearing. Fracture can sometimes be prevented by protective bracing and bisphosphonate therapy; bisphosphonate therapy has also been shown to promote healing after surgery.

Genetic testing for NF1 NF1 is inherited in an autosomal dominant fashion with sporadic mutations occurring in about 50% of patients and a 50% chance of transmission from affected individuals during each pregnancy. A mutation is detected in about 95% of individuals. If clinical criteria for NF1 are met, genetic testing is not indicated; the 5% false negative rate necessitates annual clinical follow-up of all children with suspected NF1 to detect potential complications. Furthermore, among the many pathologic mutations identified in the NF1 gene, there are few specific genotype-phenotype correlations. Deletion of the entire NF1 gene results in a more severe phenotype [29], associated with facial dysmorphism, increased predisposition for MPNST, cardiac abnormalities, and overgrowth. A 3-bp in-frame deletion in exon 17 of the NF1 gene is associated with a milder phenotype, which is Therapies for Childhood Neurofibromatosis Ardern-Holmes and North

not associated with cutaneous or plexiform neurofibromas [30]. Genetic testing has an important role in the context of prenatal testing and pre-implantation genetic diagnosis, though its prognostic value is limited by the variable expressivity characteristic of most NF1 mutations. Segmental neurofibromatosis and somatic mosaicism in both NF1 and NF2 carries a lower recurrence risk [31]. The major known differential diagnosis of NF1 is Legius syndrome, an autosomal dominant disorder due to mutations in the SPRED1 gene, which is also involved in the RasMAPK pathway [32]. Legius syndrome is characterized by café au lait spots and skinfold freckling, as well as an increased frequency of learning difficulties, but importantly, patients do not develop neurofibromas, OPGs, Lisch nodules, or bone lesions. Of patients positive for a SPRED1 mutation, 48% fulfil NF1 diagnostic criteria based on café au lait spots, freckling, and/or a positive family history of a parent with skin manifestations. It is estimated that 2% of individuals with a clinical diagnosis of NF1 have Legius syndrome; the estimated frequency is 1 in 120,000. At present, genetic screening for Legius syndrome is likely to be most useful in families with autosomal dominant café au lait spots (with or without freckling) without a mutation in the NF1 gene. Treatment: Neurofibromatosis type 1

& Treatment approaches for NF1 are diverse and depend on the specific clinical problem. General approaches to therapy are summarized under each subheading below.

Physical/occupational/speech therapy & Early intervention including physical therapy, occupational therapy, and speech therapy are recommended for children with NF1 and developmental delay. No controlled studies have evaluated the benefit of treatment. Surgery & Surgery usually is not necessary in NF1. It may be considered for selected symptomatic cutaneous and subcutaneous neurofibromas and complicated plexiform neurofibromas in NF1, as well as for large OPGs causing mass effect and hydrocephalus with significant visual impairment [33]. & Complications of surgery for plexiform neurofibromas include excessive hemorrhage and neurologic deficit due to nerve damage. & Early diagnosis and surgical resection with wide margins is the mainstay of treatment for MPNST [34, Class IV]. & Safety and efficacy of surgical correction of scoliosis in NF1 has been demonstrated in a case series including 32 children between 11 and 19 years of age with follow-up for an average of 6.5 years [35, Class IV]. & Surgery including encephaloduroarteriomyosynangiosis (known as EDAMS or pial synangiosis) may be indicated in the management of moyamoya in NF1 [36, Class IV]. Pediatric Neurology (Harvey Singer, Section Editor)

& Standard inpatient costs are associated with diagnostic testing and surgery, with significant benefits of early complete resection in the treatment of suspected MPNST. Radiotherapy/radiosurgery & Cranial radiotherapy is usually avoided in NF1 because of the increased risk of occlusive cerebral vasculopathy (moyamoya) and secondary tumor formation [37, 38, Class IV]. & Radiotherapy occasionally may be used as a palliative treatment for inoperable MPNSTs or as an adjunct to surgical resection when the risks of progression or recurrence are thought to outweigh the risks of secondary malignancy. Pharmacologic treatment & Data from the first randomized, double-blind, placebo-controlled trial of statin therapy examined the effectiveness of simvastatin in 62 children with NF1. No significant benefit was demonstrated overall, but a number of methodologic limitations were cited [39, Class II]. The potential benefit of statins is being further evaluated in an international multicenter trial using lovastatin for the treatment of cognitive dysfunction in children with NF1. & Vincristine and carboplatin chemotherapy is the current standard of care in children with symptomatic progressive OPG in NF1. The efficacy of new agents (RAD001) is under investigation. Outcomes of chemotherapy for children with NF1 treated with vincristine/ carboplatin regimens have included stabilization of vision in 40% and improvement in 31%; vision deteriorated in 29% of children studied [16, Class IV]. & Precocious puberty may require treatment with gonadotrophin analogues. & There are currently no proven medical therapies to treat plexiform neurofibromas. Early clinical trials have employed differentiating agents, antifibrotic agents, immune suppressants, and angiogenesis and farnesyltransferase inhibitors without significant benefit [40–42, Class III; 43]. Other agents are under investigation. & Aspirin is recommended for patients with evidence of vasculopathy on neuroimaging [26]. & Pain associated with nerve tumors may be treated with agents such as gabapentin, but there are no specific data reporting optimal dose or efficacy in NF1 patients. & Seizures are treated with standard antiepileptic drugs.

Emerging therapies & Multicenter phase II clinical trials are currently under way to assess the utility of the mTOR inhibitor rapamycin, the VEGFR (vascular endothelial growth factor receptor) and kinase inhibitor sorafenib, Therapies for Childhood Neurofibromatosis Ardern-Holmes and North

and the protein tyrosine kinase inhibitor imatinib in treating children with plexiform neurofibromas. Multiagent regimens include the angiogenesis inhibitor bevacizumab with the mTOR inhibitor RAD001 for MPNST, and the epidermal growth factor receptor (EFGR) inhibitor erlotinib with rapamycin, an mTOR inhibitor, for low-grade gliomas [44••, 45••]. The observation of rapidly progressive moyamoya in a child with glioblastoma treated with the angiogenesis inhibitor bevacizumab indicates that the NF1 population may be at increased risk of adverse effects from this class of medications [46, Class IV]. Neurofibromatosis type 2

NF2 is caused by mutations in the tumor suppressor gene on chromosome 22q12, which encodes the protein merlin or schwannomin. This protein has multiple functions, including a role in the organization of cell membrane proteins, cell-to-cell adhesions, cytoskeletal architecture, and cytosolic protein interactions, with downstream modification of mitogenic signalling pathways including the Ras/MAPK and phosphoinositide 3-kinase (PI3K) pathways affecting cell growth and proliferation and protein translation [47].

Diagnosis Clinical diagnosis is based on any one of the following four criteria [48•]: 1. Bilateral vestibular schwannomas or 2. First-degree relative with NF2 plus unilateral vestibular schwannoma or any two of schwannoma, meningioma, glioma, neurofibroma, or posterior subcapsular lens opacity, or 3. Unilateral vestibular schwannoma plus any two of meningioma, schwannoma, glioma, neurofibroma, or posterior subcapsular lens opacity, or 4. Multiple meningiomas (92) plus unilateral vestibular schwannoma or two of schwannoma, glioma, neurofibroma, or posterior subcapsular lens opacity. Ependymomas and gliomas are also more frequent than in the general population, as are peripheral neuropathy and ophthalmologic issues including ju- venile cataracts, retinal hamartoma, and combined hamartoma of the retinal pigmentary epithelium and retina. Café au lait spots and hypopigmented macules are seen but are less common than in NF1.

Complications The major medical complications in NF2 are due to vestibular schwannomas occurring in 90% to 95% of patients, spinal tumors in 63% to 90%, and meningiomas in 58% to 75% [47, 49]. Individuals with NF2 experience greater morbidity associated with tumors than sporadic cases, in part due to an increased growth rate of tumors in NF2. Morbidity and mortality is higher with childhood onset: one report of 74 patients calculated a 20-year survival rate of 28% for individuals symptomatic prior to 25 years of age compared with Pediatric Neurology (Harvey Singer, Section Editor)

62% for those symptomatic after age 25 [50]. Patients with multiple meningiomas and truncating mutations in the NF2 gene also carry a poorer prognosis. The presentation of NF2 varies across age groups, but symptoms secondary to vestibular schwannomas are more common in adults. About 18% of patients with NF2 present before 15 years of age (some during infancy), with greater symptomatic diversity than adults [51]. Symptoms are due to spinal cord compression, cranial nerve or peripheral nerve schwannomas, or ocular manifestations of disease that cause visual problems; optic nerve sheath meningiomas may cause complete blindness [4•]. Mononeuropathy (facial nerve palsy and foot drop) occurs less frequently, along with seizures, headaches, weight loss, skin lumps, weakness, and paresthesias [51–53]. Careful neurologic, ophthalmologic, and dermatologic examination, in addition to cranial and spinal neuroimaging, are important for diagnosis, together with examination of first-degree relatives and genetic testing. Children of affected parents may be diagnosed in early childhood, while asymptomatic. Ongoing surveillance and consideration of genetic testing is indicated for children with isolated vestibular schwannomas or meningiomas, as 10% and 20% respectively may be affected by NF2 [48•]. Optimal management of NF2 patients requires a multidisciplinary approach in a specialist center with the involvement ofexperiencedneurologists,geneticists, neurosurgeons, otolaryngologists, audiologists, ophthalmologists, radiologists, and nurses. Current recommendations for surveillance and treatment, based on consensus between treating specialists, are shown in Table 2 [54,ClassIV]. The mainstay of surveillance in asymptomatic individuals is annual clinical examination, hearing and ophthalmology evaluations, and neuroimaging, which should include MRI of the brain and spine. Children of individuals with NF2 should be screened for cataracts, which can be symptomatic in the first year of life, and for intracranial meningiomas, which may become symptomatic in the first 10 years, whereas vestibular schwannomas rarely produce symptoms before age 10 [47, 54]. At 10 years of age, presymptomatic genetic testing and genetic counseling are recommended to identify individuals at increased risk of early and severe complications, in addition to cranial and spinal MRI to identify tumors. Earlier neuroimaging studies should be considered for children with any symptoms or signs of potential complications or those from families with known severe genotypes. Thereafter, scans should bearrangedatintervalsof2to3years,or earlier if new symptoms or signs occur. Once tumors are identified, surveillance for progressive growth should be carried out every 6 to 12 months, depending on tumor size and growth rate. Three-dimensional volumetric analysis is now established as the most sensitive means of documenting vestibular schwannoma growth [55]. Surgical and medical treatment options available for tumors associated with NF2 are summarized below, but disease progression is common despite current approaches.

Genetic testing for NF2 Genetic testing is available for NF2, which, like NF1, is inherited in an autosomal dominant fashion with sporadic mutations occurring in about 50% of patients. There is a closer relationship between the genotype and phenotype in Therapies for Childhood Neurofibromatosis Ardern-Holmes and North

Table 2. Current surveillance and treatment of the major medical complications associated with neurofibromatosis type 2 Complications Surveillance Treatment Vestibular schwannoma Annual general clinical evaluation from – time of diagnosis Annual audiology evaluation from 10 years of age or earlier if symptomatic Cranial MRI study at 10 years, or earlier if symptomatic, then every 2 years from 10 to 20 years of age and every 3 years after age 20 for unaffected individuals Known vestibular schwannoma: Audiology Surgery for progressive brain stem examination and cranial MRI every compression; consider angiogenesis 6–12 months inhibitors for progressive hearing loss, other medication in clinical trial, radiosurgery (controversial) Meningioma Annual general clinical evaluation from – time of diagnosis Cranial and spinal MRI at 10 years, or earlier if symptomatic, with follow-up studies every 2 years until age 20, then yearly Known meningioma: Examination and cranial Surgery for accessible tumors. MRI every 6–12 months Antiepileptic medication. Candidate for medication in clinical trial Spinal tumors Annual general clinical evaluation from time – of diagnosis; spinal MRI at 10 years or earlier if symptomatic Known spinal tumors: Examination and Surgery for symptomatic tumors (if operable); spinal MRI every 6–12 months candidate for medication in clinical trial Ophthalmologic effects Annual ophthalmology evaluation Specialist ophthalmologic intervention

(Adapted from Evans et al. [54].)

NF2 than in NF1. Nonsense and frame-shift mutations resulting in a truncated protein product are associated with more severe disease than missense mutations or large deletion [48•]. Genetic testing has an important role in the context of prenatal testing and pre-implantation genetic diagnosis. Knowledge of the patient’s genotype and broader genetic background may become more important in understanding individual responses to novel molecularly targeted agents. Treatment: Neurofibromatosis type 2

& Surgery and supportive therapy for hearing and vision loss are currently the mainstays of therapy for NF2-associated tumors. Novel medical therapies with demonstrated efficacy will be available in the future, following controlled trials of molecularly targeted medication options. Pediatric Neurology (Harvey Singer, Section Editor)

Surgery & Surgery for vestibular schwannomas is typically reserved for large tumors associated with complete hearing loss and brainstem compression because of the surgical risk of complete hearing loss and facial nerve palsy. However, some surgeons advocate for early intervention when tumors are less than 1.5 cm in diameter [56, Class IV]. & Surgery is the primary treatment for meningiomas, but they can recur, and some tumors (such as skull base tumors) are not amenable to resection. Radiotherapy/radiosurgery & Radiation may be considered for vestibular tumors less than 3 cm to avoid the risks associated with surgery, but it is typically avoided in NF2 because of the increased risks associated with treatment, including secondary tumor formation and malignant transformation in the NF2 population [48•, 57]. & Nevertheless a recent case series has described increased overall survival and progression-free survival, compared with non-NF2 patients, following radiation treatment (mostly stereotactic radiosurgery) in 18 NF2 patients (median age 25 years) with progressive vestibular schwannoma (16%), ependymoma (6%), low-grade glioma (11%), meningioma (60%), and schwannoma/neurofibroma. This included local control of 94% of vestibular tumors, with hearing preservation for 50% [58, Class IV]. Pharmacologic treatment & Agents that have shown some promise for treatment of vestibular schwannomas include the EGFR (ErbB1) inhibitor erlotinib and a monoclonal antibody against VEGF, bevacizumab, with improvement in hearing and tumor shrinkage in a proportion of cases [59, 60,ClassIV]. & No treatment trials dedicated to the assessment of responses of NF2 patients with meningiomas have yet been undertaken, but a limited number of NF2 patients have been included with sporadic patients. Disease stabilization may be achieved with hydroxyurea, interferon, or somatostatin analogues in some cases [61, Class IV]. A recent phase II study of imatinib (targeting PDGFR, platelet-derived growth factor receptor) in 22 adults with recurrent meningioma, including one patient with NF2, showed minimal activity; ongoing studies are evaluating imatinib in combination with erlotinib, an EGFR inhibitor [62, Class III]. Assistive devices & Hearing aids offer benefit for patients with some residual hearing, and brainstem and cochlear implants have been used with success in some patients [63]. These have a more important role for adult patients than for children. Therapies for Childhood Neurofibromatosis Ardern-Holmes and North

Emerging therapies & Aconsensusstatementrecentlyidentified vestibular schwannomas and meningiomas as the key focus for development of novel medical therapy in NF2 and summarized potential candidates [64••]. Response criteria for vestibular schwannoma trials have been proposed in order to standardize monitoring and response evaluations using different agents [65]. Phase 0 and phase II trials with lapatinib (EGFR/ErbB2 inhibitor) are under way [45••]. Questions remain regarding optimal agents and indications for treatment, duration of therapy, and alternative options in the event of treatment failure. & To date, data regarding the pediatric age group are limited, and a coordinated multicenter approach is needed to assess the effectiveness of novel agents targeting the molecular pathophysiologic basis of disease in children affected by NF1 or NF2.

Disclosure No potential conflicts of interest relevant to this article were reported. References and Recommended Reading

Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance 1. Cichowski K, Jacks T. NF1 tumor suppressor gene 7. Hyman SL, Shores A, North KN. The nature and fre- function: narrowing the GAP. Cell. 2001;104 quency of cognitive deficits in children with neurofi- (4):593–604. bromatosis type 1. Neurology. 2005;65(7):1037–44. 2. McClatchey AI. Neurofibromatosis. Annu Rev Pathol. 8. Mautner VF, Kluwe L, Thakker SD, et al. Treatment of 2007;2:191–216. ADHD in neurofibromatosis type 1. Dev Med Child 3. Shilyansky C, Karlsgodt KH, Cummings DM, et Neurol. 2002;44(3):164–70. al. Neurofibromin regulates corticostriatal inhibi- 9. Payne JM, Moharir MD, Webster R, et al. Brain tory networks during working memory perfor- structure and function in neurofibromatosis type 1: mance. Proc Natl Acad Sci USA. 2010;107 current concepts and future directions. J Neurol (29):13141–6. Neurosurg Psychiatr. 2010;81(3):304–9. 4. • Ferner RE. The neurofibromatoses. Pract Neurol. 10. Dilts CV, Carey JC, Kircher JC, et al. Children and 2010;10(2):82–93. adolescents with neurofibromatosis 1: a behav- This review comprehensively presents the clinical features ioral phenotype. J Dev Behav Pediatr. 1996;17 and management approach for NF1 and NF2, including a (4):229–39. number of clinical photographs 11. Thompson HL, Viskochil D, Stevenson DA, et al. 5. Williams VC, Lucas J, Babcock MA, et al. Neurofi- Speech-language characteristics of children with bromatosis type 1 revisited. Pediatrics. 2009;123 neurofibromatosis type 1. Am J Med Genet A. (1):124–33. 2010;152A(2):284–90. 6. Ferner RE, Huson SM, Thomas N, et al. Guidelines 12. Li W, Cui Y, Kushner SA, et al. The HMG-CoA re- for the diagnosis and management of individuals ductase inhibitor lovastatin reverses the learning and with neurofibromatosis 1. J Med Genet. 2007;44 attention deficits in a mouse model of neurofibro- (2):81–8. matosis type 1. Curr Biol. 2005;15(21):1961–7. Pediatric Neurology (Harvey Singer, Section Editor)

13. Listernick R, Ferner RE, Liu GT, et al. Optic 28. Ruggieri M, Iannetti P, Clementi M, et al. Neurofi- pathway gliomas in neurofibromatosis-1: contro- bromatosis type 1 and infantile spasms. Childs Nerv versies and recommendations. Ann Neurol. Syst. 2009;25(2):211–6. 2007;61(3):189–98. 29. Mautner VF, Kluwe L, Friedrich RE, et al. Clinical 14. Thiagalingam S, Flaherty M, Billson F, et al. Neuro- characterisation of 29 neurofibromatosis type-1 fibromatosis type 1 and optic pathway gliomas: fol- patients with molecularly ascertained 1.4 Mb type-1 low-up of 54 patients. Ophthalmology. 2004;111 NF1 deletions. J Med Genet. 2010;47(9):623–30. (3):568–77. 30. Upadhyaya M, Huson SM, Davies M, et al. An ab- 15. Chang L, El-Dairi MA, Frempong TA, et al. Optical sence of cutaneous neurofibromas associated with a coherence tomography in the evaluation of neurofi- 3-bp inframe deletion in exon 17 of the NF1 gene bromatosis type-1 subjects with optic pathway glio- (c.2970-2972 delAAT): evidence of a clinically sig- mas. J AAPOS. 2010;14(6):511–7. nificant NF1 genotype-phenotype correlation. Am J – 16. Fisher MJ, Balcer L, Gutmann DH, et al. Neurofi- Hum Genet. 2007;80(1):140 51. bromatosis type 1 associated optic glioma visual 31. Evans DG, Wallace A. An update on age related outcomes following chemotherapy: an international mosaic and offspring risk in neurofibromatosis 2 multi-center retrospective analysis. Neurooncol. (NF2). J Med Genet. 2009;46(11):792. 2010;12(6):ii19–20. 32. Messiaen L, Yao S, Brems H, et al. Clinical and mu- 17. Rosser T, Packer RJ. Intracranial neoplasms in chil- tational spectrum of neurofibromatosis type 1-like dren with neurofibromatosis 1. J Child Neurol. syndrome. JAMA. 2009;302(19):2111–8. 2002;17(8):630–7. 33. Binning MJ, Liu JK, Kestle JR, et al. Optic pathway gliomas: a review. Neurosurg Focus. 2007;23(5):E2. 18. Korf BR. Plexiform neurofibromas. Am J Med Genet. 1999;89(1):31–7. 34. Ferner RE, Gutmann DH. International consensus statement on malignant peripheral nerve sheath 19. Nguyen R, Kluwe L, Fuensterer C, et al. Plexiform tumors in neurofibromatosis. Cancer Res. 2002;62 neurofibromas in children with neurofibromatosis (5):1573–7. type 1: frequency and associated clinical deficits. J Pediatr. 2011 May 27 (Epub ahead of print). 35. Koptan W, El Miligui Y. Surgical correction of severe dystrophic neurofibromatosis scoliosis: an experi- 20. Dombi E, Solomon J, Gillespie AJ, et al. NF1 plexi- ence of 32 cases. Eur Spine J. 2010;19(9):1569–75. form neurofibroma growth rate by volumetric MRI: relationship to age and body weight. Neurology. 36. Baaj AA, Agazzi S, Sayed ZA, et al. Surgical manage- 2007;68(9):643–7. ment of moyamoya disease: a review. Neurosurg Focus. 2009;26(4):E7. 21. Yang FC, Ingram DA, Chen S, et al. Nf1-dependent tumors require a microenvironment containing Nf1+/−− 37. Grill J, Couanet D, Cappelli C, et al. Radiation-in- and c-kit-dependent bone marrow. Cell. 2008;135 duced cerebral vasculopathy in children with neuro- (3):437–48. fibromatosis and optic pathway glioma. Ann Neurol. 1999;45(3):393–6. 22. Evans DG, Baser ME, McGaughran J, et al. Malignant peripheral nerve sheath tumours in neurofibroma- 38. Merchant TE, Kun LE, Wu S, et al. Phase II trial of tosis 1. J Med Genet. 2002;39(5):311–4. conformal radiation therapy for pediatric low-grade glioma. J Clin Oncol. 2009;27(22):3598–604. 23. Mautner VF, Friedrich RE, von Deimling A, et al. Malignant peripheral nerve sheath tumours in neu- 39. Krab LC, de Goede-Bolder A, Aarsen FK, et al. Effect rofibromatosis type 1: MRI supports the diagnosis of of simvastatin on cognitive functioning in children malignant plexiform neurofibroma. Neuroradiology. with neurofibromatosis type 1: a randomized con- – 2003;45(9):618–25. trolled trial. JAMA. 2008;300(3):287 94. 24. Moharir M, London K, Howman-Giles R, et al. 40. Kim A, Gillespie A, Dombi E, et al. Characteristics of Utility of positron emission tomography for tu- children enrolled in treatment trials for NF1-related mour surveillance in children with neurofibroma- plexiform neurofibromas. Neurology. 2009;73 tosis type 1. Eur J Nucl Med Mol Imag. 2010;37 (16):1273–9. (7):1309–17. 41. Packer RJ, Gutmann DH, Rubenstein A, et al. Plexi- 25. Friedrich RE, Hartmann M, Mautner VF. Malignant form neurofibromas in NF1: toward biologic-based peripheral nerve sheath tumors (MPNST) in NF1- therapy. Neurology. 2002;58(10):1461–70. affected children. Anticancer Res. 2007;27 42. Babovic-Vuksanovic D, Ballman K, Michels V, et (4A):1957–60. al. Phase II trial of pirfenidone in adults with 26. Cairns AG, North KN. Cerebrovascular dysplasia in neurofibromatosis type 1. Neurology. 2006;67 neurofibromatosis type 1. J Neurol Neurosurg Psy- (10):1860–2. chiatr. 2008;79(10):1165–70. 43. Widemann BC, Salzer WL, Arceci RJ, et al. Phase I 27. Vivarelli R, Grosso S, Calabrese F, et al. Epilepsy in trial and pharmacokinetic study of the farnesyl- neurofibromatosis 1. J Child Neurol. 2003;18:338–42. transferase inhibitor tipifarnib in children with re- Therapies for Childhood Neurofibromatosis Ardern-Holmes and North

fractory solid tumors or neurofibromatosis type I and 55. Harris GJ, Plotkin SR, Maccollin M, et al. Three-dimen- plexiform neurofibromas. J Clin Oncol. 2006;24 sional volumetrics for tracking vestibular schwannoma (3):507–16. growth in neurofibromatosis type II. Neurosurgery. 44. •• Kissil JL, Blakeley JO, Ferner RE, et al. What’s new in 2008;62(6):1314–9. neurofibromatosis? Proceedings from the 2009 NF 56. Brackmann DE, Fayad JN, Slattery III WH, et al. Early Conference: new frontiers. Am J Med Genet A. proactive management of vestibular schwannomas in 2010;152A(2):269–83. neurofibromatosis type 2. Neurosurgery. 2001;49 This article presents proceedings of the annual NF conference in (2):274–80. 2009, including advances in understanding the pathophysiol- 57. Evans DG, Birch JM, Ramsden RT, et al. Malignant ogy of NF1 and NF2 and updates regarding clinical trials transformation and new primary tumours after 45. •• Huson SM, Acosta MT, Belzberg AJ, et al. Back to the therapeutic radiation for benign disease: substantial future: proceedings from the 2010 NF Conference. Am J risks in certain tumour prone syndromes. J Med Med Genet A. 2011;155(2):307–21. Genet. 2006;43(4):289–94. This article presents the most recent updates regarding sci- 58. Wentworth S, Pinn M, Bourland JD, et al. Clinical entific advances and translation to clinical trials for NF1 and experience with radiation therapy in the manage- NF2 ment of neurofibromatosis-associated central ner- 46. Ullrich NJ, Zimmerman M, Smith E, et al. Associa- vous system tumors. Int J Radiat Oncol Biol Phys. tion of rapidly progressive moyamoya syndrome 2009;73(1):208–13. with bevacizumab treatment for glioblastoma in a 59. Plotkin SR, Stemmer-Rachamimov AO, Barker 2nd child with neurofibromatosis type 1. J Child Neurol. FG, et al. Hearing improvement after bevacizumab in 2011;26(2):228–30. patients with neurofibromatosis type 2. N Engl J 47. Asthagiri AR, Parry DM, Butman JA, et al. Neurofibro- Med. 2009;361(4):358–67. matosis type 2. Lancet. 2009;373(9679):1974–86. 60. Plotkin SR, Halpin C, McKenna MJ, et al. Erlotinib 48. • Evans DG, Neurofibromatosis type 2 (NF2): a clini- for progressive vestibular schwannoma in neurofi- cal and molecular review. Orphanet J Rare Dis. bromatosis 2 patients. Otol Neurotol. 2010;31 2009;4:16. (7):1135–43. This review article provides a comprehensive overview of clini- 61. Chamberlain MC, Glantz MJ, Fadul CE. Recurrent me- cal, genetic, and management issues for patients with NF2 ningioma: salvage therapy with long-acting somato- 49. Nunes F, MacCollin M. Neurofibromatosis 2 in the statin analogue. Neurology. 2007;69(10):969–73. pediatric population. J Child Neurol. 2003;18 62. Wen PY, Yung WK, Lamborn KR, et al. Phase II study (10):718–24. of imatinib mesylate for recurrent meningiomas 50. Otsuka G, Saito K, Nagatani T, et al. Age at symptom (North American Brain Tumor Consortium study onset and long-term survival in patients with neurofi- 01–08). Neuro Oncol. 2009;11(6):853–60. bromatosis Type 2. J Neurosurg. 2003;99(3):480–3. 63. Neff BA, Wiet RM, Lasak JM, et al. Cochlear im- 51. Evans DG, Birch JM, Ramsden RT. Paediatric pre- plantation in the neurofibromatosis type 2 patient: sentation of type 2 neurofibromatosis. Arch Dis long-term follow-up. Laryngoscope. 2007;117 Child. 1999;81(6):496–9. (6):1069–72. 52. MacCollin M, Mautner VF. The diagnosis and man- 64. •• Evans DG, Kalamarides M, Hunter-Schaedle K, et al. agement of neurofibromatosis 2 in childhood. Semin Consensus recommendations to accelerate clinical Pediatr Neurol. 1998;5(4):243–52. trials for neurofibromatosis type 2. Clin Cancer Res. 2009;15(16):5032–9. 53. Mautner VF, Tatagiba M, Guthoff R, et al. Neurofi- bromatosis 2 in the pediatric age group. Neurosur- This consensus statement addresses challenges in clinical gery. 1993;33(1):92–6. trials for NF2 and outlines current candidate medications 54. Evans DG, Baser ME, O’Reilly B, et al. Management 65. Plotkin SR, Halpin C, Blakeley JO, et al. Suggested of the patient and family with neurofibromatosis 2: a response criteria for phase II antitumor drug studies consensus conference statement. Br J Neurosurg. for neurofibromatosis type 2 related vestibular 2005;19(1):5–12. schwannoma. J Neurooncol. 2009;93(1):61–77. Comment

Treatment for plexiform neuroﬁ bromas in patients with NF1

Plexiform neurofi bromas are congenital lesions Consideration should be given to the selection of clearly associated with neurofi bromatosis type 1 (NF1). progressive lesions for inclusion in follow-up studies, They grow at variable rates, particularly in childhood, and in other prospective treatment trials to optimise and can result in substantial morbidity and early treatment response. Demonstration of stable tumour mortality.1,2 Tumours can be multiple and extensive, volume in patients with progressive disease before and cause diff ering symptoms depending on their treatment could also be consistent with treatment location, including pain and disfi gurement, functional response, potentially with signifi cant clinical benefi t if impairment of vision, mobility, bladder and bowel sustained over time. function, and respiratory compromise. Robertson and colleagues are engaged in the search Winter/Science Photo Library Dr Mark J In The Lancet Oncology, Kent Robertson and colleagues3 for potential biomarkers, and if such markers can be Published Online October 23, 2012 present the results of a phase 2 pilot study, which has identifi ed, these could substantially alter the targeting http://dx.doi.org/10.1016/ shown a reduction in size of symptomatic plexiform and response rates in treatment of symptomatic S1470-2045(12)70435-7 neurofi bromas in patients with NF1 treated with the oral patients. Few clinical trials for treatment of plexiform See Articles page 1218 kinase inhibitor imatinib mesylate. These fi ndings are neurofi bromas in NF1 have been published,6–8 and important because surgery and radiotherapy are of limited this study makes an important contribution. Data are applicability, and few established medical treatments anticipated for studies with other candidate medications are available to slow the growth or induce regression of including mTOR inhibitors, pegylated interferon, MEK these tumours. Preclinical studies in a NF1 mouse model inhibitors, other kinase inhibitors, and VEGF inhibitors. showed reduced tumour volume in response to imatinib Although change in tumour volume is an important and established the rationale for the current clinical trial endpoint, assessment of the clinical eff ect of change in plexiform neurofi bromas.4 The mouse studies were in tumour size is crucial. The authors acknowledge supported by a case report of a 3-year-old child with NF1 limitations in this study with regard to assessments and a plexiform neurofi broma that caused critical airway of the eff ect of treatment on functional outcomes. compression; treatment with imatinib resulted in a Although 30% (seven of 23) of evaluable patients reduction in tumour volume of more than 50%.4 reported subjective symptomatic improvement, this Robertson and colleagues3 report that six (26%) of change was not associated with reduced tumour bulk 23 evaluable patients aged between 3 and 52 years in all cases. The variable nature of individual morbidity (median 11 years) had a 20% or greater reduction in and the wide age range of aff ected patients pose a at least one tumour after 6 months or more of oral challenge for optimising the assessment of functional treatment with imatinib mesylate. A maximum of 38% outcomes in future clinical trials. Nevertheless, the need volume reduction was noted in one tumour. Although for objective functional outcome measures together eight (12%) of 69 individual tumours exceeded the 20% with the development of disease-specifi c mechanisms volume reduction threshold constituting treatment for assessment of quality of life in both adults and response, only one patient continued on long-term children has been recognised and is an active area of treatment. A further 36 (52%) tumours remained stable discussion among members of the NF Clinical Trials (<20% increase or decrease in volume) and 25 (36%) Consortium and international partners. progressed (≥20% increase in volume). The report by Robertson and colleagues identifi es the These fi ndings highlight the substantial variability in importance of medication tolerability to ensure sustained tumour response to treatment. The authors could not compliance, and suggests an adequate duration of identify factors clearly aff ecting treatment response, treatment of 12 months during future clinical trials of taking into account age, tumour location, or tumour these slow-growing tumours —an appropriate time size; however, larger tumours seemed to have a slightly frame. The fi nding of longer time to response in older reduced response. A previous study with the mTOR patients is interesting and warrants further study. inhibitor sirolimus indicated that non-progressive Adequate surveillance MRI and symptomatic plexiform neurofi bromas did not respond to treatment.5 monitoring should be undertaken for patients with NF1

www.thelancet.com/oncology Vol 13 December 2012 1175 Comment

and potentially complicated plexiform neurofi bromas. KNN is a member of the NF Clinical Trials Consortium along with authors on the manuscript, but has not been involved in direct collaboration on this trial. SLA-H Large multicentre trials with refi nements in study declares that she has no confl ict of interest. design, which enrol patients with a well-documented 1 Korf BR. Plexiform neurofi bromas. Am J Med Genet 1999; 89: 31–37. history and neuroimaging surveillance from a young 2 Tucker T, Friedman JM, Friedrich RE, Wenzel R, Fünsterer C, Mautner V-F. Longitudinal study of neurofi bromatosis 1 associated plexiform age, are needed to facilitate identifi cation of factors neurofi bromas. J Med Genet 2009; 46: 81–85. underlying variable treatment response to diff erent 3 Robertson KA, Nalepa G, Yang F-C, et al. Imatinib mesylate for plexiform neurofi bromas in patients with neurofi bromatosis type 1: a phase 2 trial. candidate medications. Although imatinib mesylate Lancet Oncol 2012; published online Oct 23. http://dx.doi.org/10.1016/ seems to have a modest benefi t for some patients, S1470-2045(12)70414-X. 4 Yang FC, Ingram DA, Chen S, et al. Nf1-dependent tumors require a effi cacy might be enhanced in combination with other microenvironment containing Nf1+/− and c-kit-dependent bone marrow. Cell 2008; 135: 437–48. agents. The continued cooperation between basic 5 Widemann BC, Fisher MJ, Dombi E, et al. Phase II study of the mTOR scientists and clinicians promises to improve outcomes inhibitor sirolimus for nonprogressive NF1-associated plexiform neurofi bromas: a Neurofi bromatosis Consortium study. J Clin Oncol 2010; over time for individuals with symptomatic plexiform 28 (suppl); e13601 (abstr). neurofi bromas. 6 Babovic-Vuksanovic D, Widemann BC, Dombi E, et al. Phase I trial of pirfenidone in children with neurofi bromatosis 1 and plexiform neurofi bromas. Pediatr Neurol 2007; 36: 293–300. Simone L Ardern-Holmes, Kathryn N North 7 Babovic-Vuksanovic D, Ballman K, Michels V, et al. Phase II trial of pirfenidone in adults with neurofi bromatosis type 1. Neurology 2006; TY Nelson Department of Neurology and Neurosurgery (SLA-H), 67: 1860–62. and Institute for Neuroscience and Muscle Research, Children’s 8 Gupta A, Cohen BH, Ruggieri P, Packer RJ, Phillips PC. Phase I study of Hospital at Westmead (KNN), Sydney Medical School, University thalidomide for the treatment of plexiform neurofi broma in neurofi bromatosis 1. Neurology 2003; 60: 130–32. of Sydney, NSW, Australia [email protected]

Adjuvant bevacizumab in colon cancer: where did we go wrong?

The past decade has been an exciting time for research did not meet expectations in adjuvant trials;1 but even in colorectal oncology, with basic discoveries in cancer here the results, which fell just short of signifi cance, are development and progression being translated into not inconsistent with the general rule that activity in targeted therapeutics with tangible benefi ts for advanced disease correlates with adjuvant benefi t. patients. However, it has also been a time of confusion, But if the eff ect of non-specifi c cytotoxic agents since compelling initial results have often been followed might be broadly generalisable between the biologically by disappointing or even adverse eff ects in subsequent very diff erent targets of macrometastases and Zephyr/Science Photo Library trials. This is especially true of the move to the adjuvant micrometastases, the same is not true for targeted Published Online setting, where our therapeutic aim shifts from control therapies. The two leading targeted approaches in November 16, 2012 of established metastases to the eradication of occult colorectal cancer—therapeutic antibodies against VEGF http://dx.doi.org/10.1016/ S1470-2045(12)70521-1 micrometastases. and EGFR—have both now failed unequivocally to See Articles page 1225 In the era of cytotoxic chemotherapy, the search translate to the adjuvant setting. Moreover, we are now for eff ective adjuvant therapy followed a simple but faced with the startling fi nding that they have actually, generally reliable approach: the drugs and regimens in some trials, worsened patient outcomes. most eff ective against bulky, established metastases The AVANT trial 2 was launched in December, 2004, were then investigated in the adjuvant setting, where soon after publication of phase 3 data showing they were usually also more eff ective in eradicating substantial survival benefi t with bevacizumab in micrometastases and increasing the rate of cure. In metastatic colorectal cancer.3 In AVANT, a standard bowel cancer therapy we progressed from observation fl uorouracil–oxaliplatin regimen was compared with the to single-agent fl uorouracil, to leucovorin modulation, same regimen plus bevacizumab during chemotherapy to oxaliplatin, and to capecitabine, and in each case the and continued for 1 year. This is an elegant comparison, results in randomised adjuvant trials were consistent involving 1915 patients, and therefore well-powered with predictions from preceding trials in patients with to show benefi t. The trial also had a third arm, advanced disease. Only one cytotoxic drug, irinotecan, capecitabine–oxaliplatin plus bevacizumab, which

1176 www.thelancet.com/oncology Vol 13 December 2012 Recommendations for imaging tumor response in neurofibromatosis clinical trials

Eva Dombi, MD ABSTRACT Simone L. Ardern- Objective: Neurofibromatosis (NF)-related benign tumors such as plexiform neurofibromas (PN) and Holmes, MD vestibular schwannomas (VS) can cause substantial morbidity. Clinical trials directed at these tumors Dusica Babovic- have become available. Due to differences in disease manifestations and the natural history of NF- Vuksanovic, MD related tumors, response criteria used for solid cancers (1-dimensional/RECIST [Response Evaluation Fred G. Barker, MD Criteria in Solid Tumors] and bidimensional/World Health Organization) have limited applicability. No Steve Connor, MD standardized response criteria for benign NF tumors exist. The goal of the Tumor Measurement Work- D. Gareth Evans, MD ing Group of the REiNS (Response Evaluation in Neurofibromatosis and Schwannomatosis) committee Michael J. Fisher, MD is to propose consensus guidelines for the evaluation of imaging response in clinical trials for NF tumors. Stephane Goutagny, MD, Methods: Currently used imaging endpoints, designs of NF clinical trials, and knowledge of the PhD natural history of NF-related tumors, in particular PN and VS, were reviewed. Consensus recom- Gordon J. Harris, PhD mendations for response evaluation for future studies were developed based on this review and Diego Jaramillo, MD the expertise of group members. Matthias A. Karajannis, MD Results: MRI with volumetric analysis is recommended to sensitively and reproducibly evaluate Bruce R. Korf, MD, PhD changes in tumor size in clinical trials. Volumetric analysis requires adherence to specific imaging Victor Mautner, MD recommendations. A 20% volume change was chosen to indicate a decrease or increase in tumor Scott R. Plotkin, MD, size. Use of these criteria in future trials will enable meaningful comparison of results across studies. PhD Conclusions: The proposed imaging response evaluation guidelines, along with validated clinical Tina Y. Poussaint, MD outcome measures, will maximize the ability to identify potentially active agents for patients with Kent Robertson, MD, NF and benign tumors. Neurology® 2013;81 (Suppl 1):S33–S40 PhD Chie-Schin Shih, MD GLOSSARY Brigitte C. Widemann, CR 5 complete response; NF 5 neurofibromatosis; PD 5 progressive disease; PN 5 plexiform neurofibroma; PR 5 partial MD response; RECIST 5 Response Evaluation Critera in Solid Tumors; REiNS 5 Response Evaluation in Neurofibromatosis and Schwannomatosis; SD 5 stable disease; STIR 5 short TI inversion recovery; TTP 5 time to progression; VS 5 vestibular For the REiNS schwannoma; WHO 5 World Health Organization. International Collaboration Standard criteria for response evaluation in clinical trials for solid tumors are well established (World Health Organization [WHO] criteria, Response Evaluation Criteria in Solid Tumors [RECIST]).1,2 Linear measurements are performed for their ease of use and are suitable for Correspondence to Dr. Dombi: most malignant lesions that rapidly change in size. Disease-specific recommendations have been [email protected] developed for some diseases in which linear measurements are not practical or meaningful, such as the Response Assessment in Neuro-Oncology (RANO) criteria for brain tumors.3,4 In addition, an international effort is under way to develop measurement guidelines for pediatric brain tumors, which will be applicable to neurofibromatosis type 1 (NF1)-related gliomas.

Supplemental data at www.neurology.org From the Pediatric Oncology Branch (E.D., B.C.W.), National Cancer Institute, Bethesda, MD; Department of Neurology (S.L.A.-H.), The Children’s Hospital at Westmead, Sydney, Australia; Department of Medical Genetics (D. B.-V.), Mayo Clinic, Rochester, MN; Neurosurgical Service (F.G.B.), Department of Radiology (G.J.H.), and Department of Neurology and Cancer Center (S.R.P.), Massachusetts General Hospital, Boston, MA; Department of Neuroradiology (S.C.), King’s College Hospital, London, UK; Department of Genetic Medicine (D.G.E.), MAHSC, St Mary’s Hospital, Manchester, UK; Division of Oncology (M.J.F.) and Department of Radiology (D.J.), The Children’s Hospital of Philadelphia; Department of Pediatrics (M.J.F.), The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA; Department of Neu- rosurgery (S.G.), Hôpital Beaujon, Clichy, France; Division of Pediatric Hematology/Oncology and NYU Cancer Institute (M.A.K.), NYU Langone Medical Center, New York, NY; Department of Genetics (B.R.K.), University of Alabama at Birmingham, Birmingham, AL; Department of Neurology (V.M.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Radiology (T.Y.P.), Boston Children’s Hospital, Boston, MA; and Department of Pediatrics (K.R., C.-S.S.), Riley Hospital for Children, Indianapolis, IN. REiNS International Collaboration members are listed on the Neurology® Web site at www.neurology.org. Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.

©2013AmericanAcademyofNeurology S33 The neurofibromatoses (NF), consisting of promote effective evaluation of the activity of NF1, neurofibromatosis type 2 (NF2), and novel agents and facilitate the comparison of re- schwannomatosis, are genetic tumor predispo- sults across trials. sition syndromes characterized by the development of predominantly benign nerve sheath METHODS The Tumor Measurement Group is composed of tumors. Plexiform neurofibromas (PN) in members from different disciplines, including neurology, oncology, radiology, and genetics. The group reviewed currently used imaging NF1, vestibular schwannomas (VS) and endpoints, designs of NF clinical trials, and the knowledge of the meningiomas in NF2, and schwannomas in natural history of NF-related tumors, in particular PN and VS. NF2 and schwannomatosis are the most fre- Consensus guidelines for future studies were developed based on this review and the expertise of group members. NF-related tumors quent histologically benign tumors for which are rare and there was an emphasis on proposing criteria that could clinical trials with targeted agents have been ini- be applied across multiple participating sites. When feasible, the tiated. Due to the limited applicability of RECIST guidelines were used as a template. response criteria for solid tumors and the lack of standardized response criteria for NF tu- RESULTS Current response evaluation of benign NF mors, previous trials have used a variety of pri- tumors in clinical trials. PN involve multiple nerve fascicles and branches5 and can cause substantial morbid- mary and secondary endpoints, which limits ity, including pain, disfigurement, motor dysfunction, comparison of results between trials. airway compromise, and vision loss.6,7 In early clinical The Response Evaluation in Neurofibroma- trials PN size was measured by RECIST or WHO cri- tosis and Schwannomatosis (REiNS) Tumor teria.8,9 Due to the complex shape, large size, and slow Measurement Group was formed to develop growth of PN, linear measurements can be highly var- standardized consensus recommendations for iable and long time periods are required to detect mea- imaging response evaluation in clinical trials surable change (figure 1). Therefore, more sensitive for benign NF tumors. This includes guidelines methods, such as volume segmentation, were developed 10–15 for image acquisition, target lesion selection, for the analysis of PN and schwannomas. These image interpretation by volumetric analysis, methods documented the feasibility of reproducibly measuring tumor volumes in natural history studies and trial design. We hope that the application and treatment trials for PN and VS.13,14,16–19 Using of these criteria in future clinical trials will the MEDx-based lesion detection method developed for PN, interobserver differences were less than 10% and intraobserver variation was #5%.10 For VS mea- Figure 1 Comparison of measurement sensitivity to detect change in tumor size sured using the Vitrea2 workstation, the coefficient of variation ranged from 0.6% to 6.8%.11 The first PN clinical trial using volumetric MRI analysis with time to progression (TTP) as the primary trial endpoint included the comparison of 1-dimensional (RECIST), 2-dimensional (WHO), and volumetric MRI analysis of PN.20 Volumetric analysis detected tumor progression (PN volume increase $20%) much earlier than linear measurements. The median TTP with volumetric analysis was 14.3 months, compared to 52.2 months using WHO criteria; the median TTP could not be determined by RECIST criteria.20 Thus, volumetric analysis significantly shortened both drug exposure for study subjects and the duration of the trial. In addition, this study provided valuable natural history data on PN growth. Volume increase over time appeared to be linear for all patients, with younger patients experiencing more rapid growth. The inverse relationship Axial short TI inversion recovery MRI images show a large paraspinal, abdominal, and pelvic plexiform neurofibroma at 3 time points (top to bottom: baseline, 12 months, 27 months) between age and PN growth rate has been confirmed 21–23 measured by 3 methods (left to right: 1D/RECIST, 2D/WHO, 3D/volumetric criteria). Pro- in other studies. Spontaneous PN shrinkage was not gressive disease was detected after 27 months by RECIST criteria, after 12 months by observed in the placebo arm of the study and has only WHO criteria, and after 6 months by the proposed volumetric criteria (20% volume increase, infrequently been observed in other studies.22 not shown). At the time of 2D progression, the volume increase was 57%, and by the time of 1D progression, the volume had more than doubled. RECIST 5 Response Evaluation Criteria NF2 is characterized by the development of bilateral in Solid Tumors; WHO 5 World Health Organization. VS, other intracranial and spinal schwannomas,

S34 Neurology 81 (Suppl 1) November 19, 2013 meningiomas, and ependymomas.24–26 In large NF2- analysis to measure benign NF-related tumors and associated VS natural history studies, the average growth to assess response in clinical trials. Excellent tissue in greatest diameter per year was reported to be between definition can be achieved with appropriate MRI 1.3 and 1.8 mm, corresponding to a 10%–14% increase techniques. Clinical trials require sequential imag- from the baseline averages of 12.4 and 13.0 mm.27,28 ing with fairly short intervals. Subjects with benign Another study evaluated the feasibility of volumetric tumors remain in studies for much longer time pe- assessment of VS and demonstrated increased sensitivity riods than those with malignant solid tumors and in detecting disease progression and reduced intrarater have a longer life expectancy.6 It is therefore pref- measurement variability compared to linear measure- erable to avoid CT imaging, as serial imaging results ments.11 Finally, one study described the pattern of vol- in considerable radiation exposure and the tech- ume increase of VS and meningiomas as saltatory for nique has not been validated for volumetric analysis the majority of tumors and linear or exponential for of NF tumors. others.29 Volumetric analysis of MRIs has been recom- Volumetric MRI analysis accounts for every part of mended to determine changes in tumor size30 and has the tumor and thus reflects the actual size of the lesion been incorporated into clinical trials targeting NF2- more closely than linear measurements. It is less sensitive related VS.17,18,31 to differences in body position between scans and can reproducibly detect small changes over time (figure 2). Guidelines for response evaluation of benign NF tumors Since every tumor-containing slice is included in the in clinical trials. Image acquisition and analysis. The analysis, volumetric analysisrequiresexcellentimage working group recommends MRI and volumetric quality. In order to achieve consistent high-quality

Figure 2 Examples of PN volume change over time

Small incremental changes are demonstrated in a complex large abdominal and flank plexiform neurofibroma (PN) with consistent upward trend through several investigational treatments (A). Extended disease stabilization of a back PN in a patient receiving peginterferon alfa-2b (B). PN growth accelerated upon discontinuation of treatment and slowed again when the patient restarted peginterferon alfa-2b. While in most cases PN growth is linear over extended periods, some measurement variation is not uncommon, as demonstrated by the example of a large neck and chest PN (C). The first observer performed the volumetric analysis prospectively and a second observer repeated the analysis at the end of the observation period while blinded to the chronological order of the scans.

Neurology 81 (Suppl 1) November 19, 2013 S35 image acquisition and to minimize the variability of Target lesions: Identification, considerations and chal- volumetric readings, a detailed section on image acqui- lenges. Patients with NF often present with more than sition should be included in study protocols. one symptomatic tumor. Ideally the entire tumor bur- The MRI acquisition protocol should be opti- den should be imaged at study entry. In most cases, the mized for tumor type and tumor location. Images most clinically significant lesion can be identified and intended for volumetric analysis need to be per- used as the target lesion to evaluate treatment response, formed without gaps between slices. The target tumor and other disease sites can be monitored as nontarget should be positioned close to the center of the imag- lesions. The target lesion should meet minimum size ing field and the outer edge of the tumor should be criteria, be seen on at least 3 imaging slices, and have within the field of view. Peripheral nerve sheath reasonably well-defined contours in all dimensions. tumors can be well visualized without the use of con- Recommended minimum tumor sizes for measurable trast agents on short TI inversion recovery (STIR) disease are 3 cm3 for PN and 1 cm3 for VS. Most sequences because they have high signal intensity lesions $3.0 cm in longest diameter will have a volume relative to normal tissues. Small lesions, such as some greater than 3 cm3, and lesions $1.5 cm a volume over orbital, facial, or paraspinal tumors, require imaging 1 cm.3 Central review can help in assessing the mea- with thin slices using small voxel sizes. Obtaining surability of questionable lesions. The target lesion complete coverage of extensive lesions can be chal- should be distinguishable from the surrounding tissues. lenging. MRI scanners capable of reconstructing Some tumors, while clinically very relevant, may not imaging series from several body segments into have good tissue definition on MRI (figure 3, A and whole-body images are now available and whole-body B). In case of disease progression, adjacent tumors can scanning is increasingly affordable. Using multiple become confluent and no longer independently mea- phased-array coil technology, whole-body STIR surable (for example, collision tumors in NF2 VS). In imaging can be accomplished in less than an hour. addition, adjacent lymph nodes can be difficult to sep- Tumor volume can also be calculated from indepen- arate from PN and are prone to size fluctuations, dent series. For best alignment of separate series, 2 to enough to give the impression of significant volume 5 slices of complete overlap between the series is change if the target lesion is small. advised. Image orientation should remain the same Lesions previously treated with locoregional therapy throughout the study. Even slight changes in orienta- such as radiation should not be selected as target lesions tion can result in partial overlap between series. STIR unless growth has been documented since the interven- sequences can be performed on 1.5T or 3T MRI scan- tion. Similarly, following partial tumor resection, post- ners, although magnetic field inhomogeneity resulting surgical changes and edema may interfere with in signal intensity variation is more common using 3T meaningful response evaluation (figure 3, C and D). magnets when imaging with large fields of view. Motion can blur the edge of lesions; regions espe- The challenge in imaging VS is their relatively cially prone to motion include the parapharyngeal small size. High-resolution postcontrast T1 com- space, diaphragm, mesenteric structures, and extremi- pletely covering the target area is the MRI sequence ties. Motion artifact is most relevant for small tumors best suited for volumetric measurement. The slice with high surface to volume ratios; at tumor sizes above thickness should be no more than 1 mm. Fat suppres- 100 cm3 the effect of motion is usually negligible. sion is required in postsurgical VS cases to differenti- Metal instrumentation, such as spinal rods, dental ate tumor from fat packing. braces, or cochlear/brainstem implants, causes charac- Table e-1 on the Neurology® Web site at www. teristic distortion on MRI that is dependent on the neurology.org provides examples of recommended magnetic field strength and positioning within the imaging parameters for PN and VS. The parameters scanner, and can therefore vary between scans (figure may vary depending on the type of scanner, tumor 3, E and F). If part of the target tumor is obscured or type, and location, but consistent use at each response distorted by metallic artifact, the tumor may still be evaluation and across multiple sites is required for measurable as long as that part of the lesion can con- optimal analysis. In multicenter studies, it is sistently be excluded from the analysis. The potential important for quality assurance to document each need for future surgery or metal implants should be site’sabilitytocomplywiththeimagingprotocol considered prior to enrollment in a trial. prior to starting enrollment. One way to achieve For very large tumors, partial volume measure- identical image acquisition across participating sites is ment between reproducibly visualized anatomical to distribute an optimized sample Digital Imaging and landmarks can be considered, but should aim to Communications in Medicine dataset and duplicate the include the bulk of the lesion. imaging parameters from that dataset at each site. We Some PN have nodular components that appear plan to provide access to sample images on the REiNS encapsulated and separated from the surrounding Web site www.reinscollaboration.org. tumor in all directions (figure 4). These nodules can

S36 Neurology 81 (Suppl 1) November 19, 2013 Volumetric results can differ based on the method Figure 3 Considerations for the selection of target lesions for volumetric assessment of analysis; therefore, the same method should be used throughout a study and across all participating institutions, ideally with central review. The analysis method should be validated to determine variation within the same dataset as a reflection of precision, and variation in trends over time as an indicator of accuracy in segmenting the same structures at different time points. Response criteria. Response categories are established to differentiate tumors that are shrinking, stable, or growing. These categories are arbitrary and were designed to minimize interrater variability. Significant changes in tumor size, as defined by RECIST or WHO criteria, can be easily recognized. Targeted agents in NF may not result in substantial tumor shrinkage, but rather lead to disease stabilization or minor shrinkage. The goal of volumetric MRI analysis for response evaluation in NF is to reproducibly detect small changes that would not be otherwise discernible. Based on the close intraobserver and interobserver agreement of repeated volumetric MRI analyses,10,11 the group agreed on a 20% volume change to indicate a decrease or increase in tumor size. Therefore, the recommended volumetric response categories for benign NF tumors are defined as follows: • Complete response (CR): Disappearance of the target lesion. • Partial response (PR): Decrease in the volume of the target lesion by 20% or more compared to

Volumetric analysis is only feasible on lesions with well-defined borders. The superficial flank the baseline. The PR is considered unconfirmed plexiform neurofibroma (PN) shown on axial (A) and coronal (B) short TI inversion recovery at the first detection, confirmed when observed MRI lacks tissue contrast (arrowheads) and it is not suitable for volume measurement. again within 3–6 months, and sustained when Edema within a tumor or surrounding tissue affects the lesion volume (C, D). Image C shows the response is maintained for 6 months or a facial PN 2 months after debulking surgery. The tumor volume gradually decreased over the next 10 months until the complete resolution of postsurgical changes (D). Metal in the longer. imaging field results in image distortion on MRI (arrows), and the position of metal artifact • Progressive disease (PD): Increase in the volume may vary between scans (E, F). of the target lesion by 20% or more compared to baseline or the time of best response after doc- be independently measured and may serve as target umenting a PR. The appearance of new lesions lesions. The growth rate of nodular lesions may or unequivocal progression of existing nontarget exceed the growth rate of the surrounding tumor.32 lesions is also considered PD. If the nodular component is selected as the target • Stable disease (SD): Insufficient volume change lesion, changes in that nodule as opposed to the entire to qualify for either PR or PD. PN should be used to determine response. Highly disproportionate growth within parts of a tumor or Table 1 illustrates equivalent size changes in spher- rapid growth exceeding that expected for PN should ical lesions using different measurement methods. raise concern for malignant transformation and Considerations for trial design and selection of endpoints prompt further investigation. using volumetric response evaluation. Many of the molec- Image interpretation by volumetric analysis. Several ularly targeted agents evaluated for the treatment of methods are available for volumetric evaluation of NF-related tumors are thought to be more likely to medical images. Simple systems use a graphic tool extend the TTP than to result in tumor shrinkage. to manually outline the target area. More sophisti- Progression-free survival as a study endpoint requires cated segmentation methods use complex algorithms a control population. There is no established histori- to define a region of interest that displays specific cal control for all NF populations. Data from one pla- imaging characteristics; some of these methods were cebo-controlled pediatric trial for PN are available specifically developed for NF-related tumors.10–13,15 and are currently used as a historical control for

Neurology 81 (Suppl 1) November 19, 2013 S37 study. A correlation between response on imaging Figure 4 Progression in target and nontarget lesions and overall survival or clinical improvement has not been established for most benign NF tumors. If feasible, in addition to imaging response, evaluation for clinical benefit should be incorporated into clinical trials as endpoints, including patient-reported and functional outcomes. Since spontaneous regression of NF tumors is rare, imaging response can be evaluated without placebo control and in patients without a prior history of progression. Clinical studies for NF take longer than typical cancer trials. Even with the use of sensitive detection The diffuse face and neck plexiform neurofibroma shown on axial short TI inversion recovery methods, tumor progression and response may occur MRI has a well-circumscribed nodular component on the left side. The complete volume of the slowly, over years rather than months. Compared with lesion increased from 1,870 mL at the first time point (A) to 2,015 mL (8% increase) at the second time point (B) to 2,283 mL (22% increase) on the final evaluation (C). Concurrently, the vol- cancer trials, longer restaging intervals are sufficient, ume of the nodular component increased from 28.2 mL to 34.3 mL (22% increase) and then to such as every 3–4 months for the first year on trial 63.0 mL (84% increase). Determination of disease progression depends on whether the entire and subsequently every 6 months. Allowing subjects lesion or the nodular component is selected as the target lesion at trial entry. with minimal tumor shrinkage at 6 months (10–15% decrease) to remain on treatment for up to 12 months several other studies.33,34 This control population is can maximize the identification of potentially active only valid for trials with identical eligibility criteria agents while minimizing exposure to inactive agents. and study design, as TTP is influenced by age, tumor The natural history of NF-related tumors should growth rate, tumor size, and restaging intervals.20 also be considered in the design of trials. Several stud- Due to the slowly progressive nature of most ies have described more rapid growth rates of PN in NF-related tumors, prolonged stable disease without younger children compared to older children or any intervention is common. Therefore, disease stability adults.21–23 Therefore, stratification based on age or can only be considered a response in subjects with docu- progression status could be considered for clinical mented imaging progression of a tumor for which linear trials evaluating TTP as the primary endpoint. growth is expected. Ideally, progression at the time of enrollment should be documented using the same FUTURE PLANS The consensus guidelines provided method of analysis that will be used in the clinical trial. here are based on current knowledge and experience. The need for an adequate control population and With new information, revisions may be implemented. the requirement of progressive disease at the time of At this time, our understanding of the natural history of enrollment in a trial with TTP as the primary endpoint NF1, NF2, and schwannomatosis is incomplete. Prior may affect the rate of accrual, as progression may be studies describing the growth pattern of NF-related tu- documented in only a subset of candidates and com- mors are limited to relatively short observation periods peting trials without a control group may be selected of 1–4 years. Long-term prospective natural history by investigators or potential research participants. studies are needed in order to better characterize tumor The objective response rate is defined as the pro- growth in all age groups and tumor types. Additional portion of subjects experiencing a PR or CR in a efforts are under way to study the correlation of changes in tumor size with changes in patient-reported and Table 1 Equivalent changes in the size of functional outcomes. Where a correlation between spherical lesions by 1-dimensional, 2-dimensional, or 3-dimensional increasing tumor size and the development of morbid- measurement ity can be established, it can be assumed that agents resulting in prolonged disease stabilization may result in 2 3 RECIST 1D (2r) WHO 2D (pr )Volume3D(4/3pr ) patient benefit by preventing the development of new 230% PRa 250% PRa 266% morbidity. Volumetric assessment methods currently in 27% 214% 220% PRa use for NF may differ in their sensitivity to detect

6% 13% 20% PDa change over time. As part of the REiNS Collaboration,

12% 25% PDa 40% the Tumor Measurement Working Group is planning pilot studies to evaluate the level of agreement between 20% PDa 44% 73% methods. Finally, volumetric MRI analysis is time and Abbreviations: RECIST 5 Response Evaluation Criteria in resource intensive and requires central review for the Solid Tumors; WHO 5 World Health Organization. most consistent results. The development of methods a Change required for partial response (PR) or progressive disease (PD) as defined by RECIST, WHO, or volumetric that can be performed more easily and be incorporated criteria. into routine clinical practice should be pursued.

S38 Neurology 81 (Suppl 1) November 19, 2013 AUTHOR CONTRIBUTIONS B. Korf serves on the board of directors of the Children’sTumorFounda- E Dombi: drafting the manuscript, study concept, interpretation of data. SL tion, as a senior advisor to the Neurofibromatosis Therapeutic Acceleration Ardern-Holmes: revising the manuscript for content, study concept, interpre- Program, and as a member of the board of scientific counselors to the tation of data. D Babovic-Vuksanovic: revising the manuscript for content, NHGRI. He is on the editorial boards of Genetics in Medicine, Drugs in study concept, interpretation of data. FG Barker: revising the manuscript Context, Journal of Genomes and Exomes,andCurrent Protocols in Human for content, study concept, interpretation of data. S Connor: revising the Genetics. He has received royalties from the publication of Human Genetics manuscript for content, study concept, interpretation of data. DG Evans: and Genomics, Medical Genetics at a Glance,andCurrent Protocols in Human revising the manuscript for content, study concept, interpretation of data. Genetics from Wiley and from the publication of Principles and Practice of MJ Fisher: revising the manuscript for content, study concept, interpretation Medical Genetics from Elsevier. He has received honoraria for speaking of data. S Goutagny: revising the manuscript for content, study concept, engagements from Washington University, the American Academy of interpretation of data. GJ Harris: revising the manuscript for content, study Pediatrics, Columbus Regional Medical Center, Cambridge Healthtech concept, interpretation of data. D Jaramillo: revising the manuscript for con- Institute, the American College of Medical Genetics and Genomics, Case tent, study concept, interpretation of data. MA Karajannis: revising the man- Western University, and KSZ Children’s Hospital of Korea. He received uscript for content, study concept, interpretation of data. BR Korf: revising research support from Novartis for serving as a principal investigator and he the manuscript for content, study concept, interpretation of data. V Maut- also receives research support from the Children’s Tumor Foundation, ner: revising the manuscript for content, study concept, interpretation of Department of Defense grants W81XWH-12-1-0155, W81XWH-05-1- data. SR Plotkin: revising the manuscript for content, study concept, inter- 615, and W81XWH-11-1-0671, and from the NIH/NICHD for grant pretation of data. TY Poussaint: revising the manuscript for content, study 2P30HD038985-06A2. V. Mautner reports no disclosures. S. Plotkin has concept, interpretation of data. K Robertson: revising the manuscript for been reimbursed by the American Academy of Neurology and the Children’s content, study concept, interpretation of data. C-S Shih: revising the manu- Tumor Foundation for travel for educational activities. He has received script for content, study concept, interpretation of data. BC Widemann: research support from the Department of Defense (W81XWH-091-0182, revising the manuscript for content, study concept, interpretation of data. NF050202, W81XWH-12-1-0155, PI), the Children’sTumorFoundation (PI), and Johns Hopkins Medical Institutes (site PI). T. Poussaint receives STUDY FUNDING research support as the principal investigator of the Neuroimaging Center of the Pediatric Brain Tumor Consortium (NIH-NCI U01CA81456-14). This research was supported by the Intramural Research Program of the She is associate editor for Pediatric Neuroradiology,aswellasNeurographics, NIH, National Cancer Institute, Center for Cancer Research. She is also a member of the NCI Clinical Imaging Steering Committee. K. Robertson receives research support from the Department of Defense DISCLOSURE (NF080099 and NF100031). C. Shih received research support from the E. Dombi reports no disclosures. S. Ardern-Holmes served on a scientific Department of Defense, award number W81XWH-11-1-0137- DOD, and advisory board for Novartis Pharmaceuticals Australia, received funding for from Pfizer, grant number LMID L1102860. B. Widemann is a member of a trip from Novartis Pharmaceuticals Australia, and receives research support the scientific advisory board of the Neurofibromatosis Therapeutic Acceler- from the Children’s Tumor Foundation of Australia. D. Babovic-Vuksanovic ation Program. She is a member of the editorial board of The Oncologist and serves as an editorial board member of the Journal of Pediatric Neurology and an associate editor of Frontiers in Pediatric Oncology. Go to Neurology.org for Acta Medica Academica and received research support from the Children’s full disclosures. Tumor Foundation for genetics research. Dr. Babovic-Vuksanovic also served as a scientific reviewer for an NF Clinical Trials Consortium. F. Barker Received May 17, 2013. Accepted in final form August 13, 2013. served as a scientific reviewer for the Department of Defense CDMRP panels on neurofibromatosis and tuberous sclerosis. He serves as a section editor for REFERENCES Neurosurgery and has received travel expenses for lectures and educational 1. Eisenhauer EA, Therasse P, Bogaerts J, et al. New response activities not funded by industry. S. Connor reports no disclosures. D. Evans evaluation criteria in solid tumours: revised RECIST has served on the scientific advisory boards of the Breast Cancer Campaign guideline (version 1.1). Eur J Cancer 2009;45:228–247. and the Genesis Breast Cancer Prevention Appeal. He is on the editorial 2. Miller AB, Hoogstraten B, Staquet M, Winkler A. board of Familial Cancer. He received research support from the Samantha Reporting results of cancer treatment. Cancer 1981;47: Dickenson Brain Tumor Trust, Cancer Research-UK, the Children’s Tumor – Foundation, the Association of International Cancer Research, the Medical 207 214. Research Council, the British Skin Foundation, CLAHRC for Greater Man- 3. Wen PY, Macdonald DR, Reardon DA, et al. Updated chester, CMFT RfPB, BDRF, Genome Canada, Genesis Breast Cancer response assessment criteria for high-grade gliomas: response Prevention Appeal, and Children with Cancer UK. M. Fisher received reim- assessment in neuro-oncology working group. J Clin Oncol bursement from the Children’s Tumor Foundation to attend their annual 2010;28:1963–1972. Neurofibromatosis Conference, is funded by the Department of Defense 4. van den Bent MJ, Wefel JS, Schiff D, et al. Response (W81XWH-12-1-0155, W81XWH-05-1-0615), Thrasher Research Fund, assessment in neuro-oncology (a report of the RANO ’ Children s Tumor Foundation, and Sarcoma Alliance for Research through group): assessment of outcome in trials of diffuse low- Collaboration, and received research support from the Pediatric Low grade gliomas. Lancet Oncol 2011;12:583–593. Grade Astrocytoma Foundation, Bayer, Children’s Discovery Institute, 5. Korf BR. Plexiform neurofibromas. Am J Med Genet NIH (NR009651-01), and the Department of Defense (W81XWH-08-1- – 0051). S. Goutagny reports no disclosures. G. Harris serves on the scientific 1999;89:31 37. advisory board of Fovia, Inc. D. Jaramillo serves on the editorial boards of 6. Kim A, Gillespie A, Dombi E, et al. Characteristics of Radiology and Pediatric Radiology. He has received honoraria for speaking children enrolled in treatment trials for NF1-related plex- engagements from Sheikh Khalifa Medical City, Massachusetts General Hos- iform neurofibromas. Neurology 2009;73:1273–1279. pital, Lucile Packard Children’s Hospital, and Boston Children’s Hospital. 7. Prada CE, Rangwala FA, Martin LJ, et al. Pediatric plex- He received research support from Genzyme. He also served as a legal case iform neurofibromas: impact on morbidity and mortality reviewer for Ford and Reminger Co., LPA. M. Karajannis served on a sci- in neurofibromatosis type 1. J Pediatr 2012;160:461–467. entific advisory board for Bayer Ag and on a peer review panel for the 8. Gupta A, Cohen BH, Ruggieri P, Packer RJ, Phillips PC. Department of Defense/CDMRP Neurofibromatosis Program. He has Phase I study of thalidomide for the treatment of plexi- received honoraria for speaking engagements from the German Cancer form neurofibroma in neurofibromatosis 1. Neurology Research Center. He has received research support from the NIH as primary – investigator on grant R01CA164295 in 2012 and as co-investigator on grant 2003;60:130 132. R01CA152975. He also received research support from St. Baldrick’sFoun- 9. Widemann BC, Salzer WL, Arceci RJ, et al. Phase I trial dation, Children’s Tumor Foundation, Ian’s Friends Foundation, Pediatric and pharmacokinetic study of the farnesyltransferase Low Grade Astrocytoma Foundation, and Making Headway Foundation. inhibitor tipifarnib in children with refractory solid tumors

Neurology 81 (Suppl 1) November 19, 2013 S39 or neurofibromatosis type I and plexiform neurofibromas. 22. Nguyen R, Dombi E, Widemann BC, et al. Growth J Clin Oncol 2006;24:507–516. dynamics of plexiform neurofibromas: a retrospective 10. Solomon J, Warren K, Dombi E, Patronas N, cohort study of 201 patients with neurofibromatosis 1. Widemann B. Automated detection and volume measure- Orphanet J Rare Dis2012;7:75. ment of plexiform neurofibromas in neurofibromatosis 23. Korf B. Natural history of plexiform neurofibromas in 1 using magnetic resonance imaging. Comput Med Imag- NF1. In: Children’s Tumor Foundation Conference ing Graph 2004;28:257–265. 2012; 2012; New Orleans. 11. Harris GJ, Plotkin SR, Maccollin M, et al. Three-dimensional 24. Evans DG, Moran A, King A, Saeed S, Gurusinghe N, volumetrics for tracking vestibular schwannoma growth in Ramsden R. Incidence of vestibular schwannoma and neurofibromatosis type II. Neurosurgery 2008;62:1314– neurofibromatosis 2 in the North West of England over 1319; discussion 1319–1320. a 10-year period: higher incidence than previously 12. Weizman L, Hoch L, Ben Bashat D, et al. Interactive thought. Otol Neurotol 2005;26:93–97. segmentation of plexiform neurofibroma tissue: method 25. Parry DM, Eldridge R, Kaiser-Kupfer MI, Bouzas EA, and preliminary performance evaluation. Med Biol Eng Pikus A, Patronas N. Neurofibromatosis 2 (NF2): clinical Comput 2012;50:877–884. characteristics of 63 affected individuals and clinical evidence 13. Babovic-Vuksanovic D, Ballman K, Michels V, et al. for heterogeneity. Am J Med Genet 1994;52:450–461. Phase II trial of pirfenidone in adults with neurofibroma- 26. Evans DG, Huson SM, Donnai D, et al. A clinical study tosis type 1. Neurology 2006;67:1860–1862. of type 2 neurofibromatosis. Q J Med 1992;84:603–618. 14. Poussaint TY, Jaramillo D, Chang Y, Korf B. Interob- 27. Slattery WH 3rd, Fisher LM, Iqbal Z, Oppenhiemer M. server reproducibility of volumetric MR imaging measure- Vestibular schwannoma growth rates in neurofibromatosis ments of plexiform neurofibromas. AJR Am J Roentgenol type 2 natural history consortium subjects. Otol Neurotol 2003;180:419–423. 2004;25:811–817. 15. Cai W, Kassarjian A, Bredella MA, et al. Tumor burden in 28. Peyre M, Goutagny S, Bah A, et al. Conservative manage- patients with neurofibromatosis types 1 and 2 and schwan- ment of bilateral vestibular schwannomas in neurofibro- nomatosis: determination on whole-body MR images. matosis type 2 patients: hearing and tumor growth results. Radiology 2009;250:665–673. Neurosurgery 2013;72:907–913. 16. Jakacki RI, Dombi E, Potter DM, et al. Phase I trial of 29. Dirks MS, Butman JA, Kim HJ, et al. Long-term natural pegylated interferon-alpha-2b in young patients with plex- history of neurofibromatosis Type 2-associated intracranial iform neurofibromas. Neurology 2011;76:265–272. tumors. J Neurosurg 2012;117:109–117. 17. Plotkin SR, Halpin C, McKenna MJ, Loeffler JS, 30. Plotkin SR, Halpin C, Blakeley JO, et al. Suggested Batchelor TT, Barker FG 2nd. Erlotinib for progressive response criteria for phase II antitumor drug studies for vestibular schwannoma in neurofibromatosis 2 patients. neurofibromatosis type 2 related vestibular schwannoma. Otol Neurotol 2010;31:1135–1143. J Neurooncol 2009;93:61–77. 18. Karajannis MA, Legault G, Hagiwara M, et al. Phase II 31. Plotkin SR, Singh MA, O’Donnell CC, Harris GJ, trial of lapatinib in adult and pediatric patients with neu- McClatchey AI, Halpin C. Audiologic and radiographic rofibromatosis type 2 and progressive vestibular schwan- response of NF2-related vestibular schwannoma to erloti- nomas. Neuro Oncol 2012;14:1163–1170. nib therapy. Nat Clin Pract Oncol 2008;5:487–491. 19. Babovic-Vuksanovic D, Widemann BC, Dombi E, et al. 32. Meany H, Dombi E, Reynolds J, et al. 18-fluorodeoxyglu- Phase I trial of pirfenidone in children with neurofibro- cose-positron emission tomography (FDG-PET) evaluation matosis 1 and plexiform neurofibromas. Pediatr Neurol of nodular lesions in patients with Neurofibromatosis type 2007;36:293–300. 1 and plexiform neurofibromas (PN) or malignant periph- 20. Widemann B, Dombi E, Gillespie A, et al. Phase II ran- eral nerve sheath tumors (MPNST). Pediatr Blood Cancer domized, flexible cross-over,double-blinded,placebo- 2013;60:59–64. controlled trial of the farnesyltransferase inhibitor (FTI) 33. Widemann B, Babovic-Vuksanovic D, Dombi E, et al. tipifarnib (R115777) in pediatric patients (pts) with neu- Phase II trial of pirfenidone in children and young adults rofibromatosis type 1 (NF1) and progressive plexiform with neurofibromatosis type 1 (NF1) and progressive plex- neurofibromas (PN). In: Children’s Tumor Foundation iform neurofibromas (PN). In: Children’s Tumor Foun- Conference; 2009; Portland, OR, 2009. dation Conference; 2009; Portland, OR, 2009. 21. Dombi E, Solomon J, Gillespie AJ, et al. NF1 plexi- 34. Weiss B, Fisher M, Dombi E, et al. Phase II study of the form neurofibroma growth rate by volumetric MRI: mTOR inhibitor sirolimus for non-progressive NF1-associated relationship to age and body weight. Neurology 2007; plexiform neurofibormas: a Neurofibromtosis Consortium 68:643–647. Study. In: ISPNO; 2010; Vienna, Austria, 2010: ii43.

S40 Neurology 81 (Suppl 1) November 19, 2013 Functional outcome measures for NF1-associated optic pathway glioma clinical trials

Michael J. Fisher, MD ABSTRACT Robert A. Avery, DO Objective: The goal of the Response Evaluation in Neurofibromatosis and Schwannomatosis Jeffrey C. Allen, MD Visual Outcomes Committee is to define the best functional outcome measures for future neuro- Simone L. Ardern- fibromatosis type 1 (NF1)-associated optic pathway glioma (OPG) clinical trials. Holmes, MD Methods: The committee considered the components of vision, other ophthalmologic parameters Larissa T. Bilaniuk, MD affected by OPG, potential biomarkers of visual function, and quality of life measures to arrive at Rosalie E. Ferner, MD consensus-based, evidence-driven recommendations for objective and measurable functional David H. Gutmann, MD, endpoints for OPG trials. PhD Robert Listernick, MD Results: Visual acuity (VA) assessments using consistent quantitative testing methods are recom- Staci Martin, PhD mended as the main functional outcome measure for NF1-OPG clinical trials. Teller acuity cards Nicole J. Ullrich, MD, are recommended for use as the primary VA endpoint, and HOTV as a secondary endpoint once PhD subjects are old enough to complete it. The optic disc should be assessed for pallor, as this Grant T. Liu, MD appears to be a contributory variable that may affect the interpretation of VA change over time. For the REiNS Given the importance of capturing patient-reported outcomes in clinical trials, evaluating visual International quality of life using the Children’s Visual Function Questionnaire as a secondary endpoint is also Collaboration proposed. Conclusions: The use of these key functional endpoints will be essential for evaluating the efficacy of future OPG clinical trials. Neurology® 2013;81 (Suppl 1):S15–S24 Correspondence to Dr. Fisher: [email protected] GLOSSARY CVFQ 5 Children’s Visual Function Questionnaire; logMAR 5 logarithm of the minimum angle of resolution; MS 5 multiple sclerosis; NF1 5 neurofibromatosis type 1; OCT 5 optical coherence tomography; OPG 5 optic pathway glioma; PFS 5 progression-free survival; QOL 5 quality of life; REiNS 5 Response Evaluation in Neurofibromatosis and Schwannomatosis; RNFL 5 retinal nerve fiber layer; TAC 5 Teller acuity cards; VA 5 visual acuity; VEP 5 visual evoked potential; VF 5 visual field.

Optic pathway gliomas (OPG) arise in 15%–20% of children with neurofibromatosis type 1 (NF1), occur preferentially in young children compared with adolescents or adults, and cause vision loss in as many as half of those affected.1 In this regard, the main objective in clinical management of these tumors is preservation of visual function. Although prognostic factors have been identified, there are currently no reliable indicators of future visual loss. This absence of prognostic signs has led clinicians to avoid initiating treatment until visual function has declined. When treatment is indicated, NF1-OPG are typically managed with a combination of carboplatin and vincristine—an approach that has not changed in 15 years.2 To date, OPG clinical trials have focused on imaging outcomes, with tumor response and/or progression-free survival used as measures of treatment success.2–4 However, increasing evidence Supplemental data at www.neurology.org From the Division of Oncology (M.J.F.), Neuroradiology Section, Department of Radiology (L.T.B.), and Neuro-Ophthalmology Service (G.T.L.), The Children’s Hospital of Philadelphia; Department of Pediatrics (M.J.F.) and Departments of Neurology and Ophthalmology (G.T.L.), The Perelman School of Medicine at the University of Pennsylvania, Philadelphia; Departments of Neurology, Ophthalmology, and Pediatrics (R.A.A.), Gilbert Family Neurofibromatosis Institute, Children’s National Medical Center, Washington, DC; Departments of Pediatrics and Neurology (J.C.A.), NYU Cancer Institute, NYU Langone Medical Center, New York, NY; Children’s Hospital at Westmead Clinical School (S.L.A.-H.), The University of Sydney, Australia; Department of Neurology (S.L.A.-H.), The Children’s Hospital at Westmead, Sydney, Australia; University of Pennsylvania School of Medicine (L.T.B.), Philadelphia; Department of Neurology (R.E.F.), Guy’s and St. Thomas’ NHS Foundation Trust and Institute of Psychiatry, King’s College London; Department of Neurology (D.H.G.), Washington University School of Medicine, St. Louis, MO; Department of Pediatrics (R.L.), Feinberg School of Medicine, Northwestern University; Ann & Robert H. Lurie Children’s Hospital of Chicago (R.L.); Pediatric Oncology Branch (S.M.), National Cancer Institute, National Institutes of Health, Bethesda, MD; and Department of Neurology (N.J.U.), Boston Children’s Hospital, Harvard Medical School, Boston, MA. REiNS International Collaboration members are listed on the Neurology® Web site at www.neurology.org. Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.

©2013AmericanAcademyofNeurology S15 from case reports, case series, and larger studies OPG (optic disc appearance, strabismus, indicates that imaging outcomes do not corre- nystagmus, and proptosis), potential biomarkers late with visual outcomes following treat- of visual function (visual evoked potential and ment.5–7 In fact, in a large multi-institutional optical coherence tomography), and quality retrospective review, only one-third of subjects of life measures to arrive at consensus-based, had concordant visual and imaging outcomes.8 evidence-driven recommendations for func- Since the primary goal of treatment is preser- tional endpoints for OPG trials (table 1). vation of visual function, therapeutic success should be based on visual rather than imaging THE BEST FUNCTIONAL ENDPOINT Visual acuity. endpoints. In order to better understand treat- Visual acuity (VA) reflects visual pathway integrity, ment outcomes for this tumor, future OPG making it an ideal candidate to objectively measure clinical trials will need to mandate functional the visual impact of an OPG. It is likely the most endpoints as primary outcome measures. important functional ophthalmologic feature, as modest amounts of VA loss can affect activities of daily living.9,10 Response Evaluation in Neurofibromatosis There is good test-retest reliability, assessments can be and Schwannomatosis (REiNS) is an interna- standardized, and the intervals of change (lines on an tional collaborative initiative designed to eye chart) are universally understood and quantifiable. develop standardized criteria for determining Furthermore, ophthalmologists and ophthalmology treatment response in patients with NF1, technicians universally understand how to perform NF2, and schwannomatosis. The overall acuity testing. objective is to identify robust endpoints that VA testing has been used reliably and is sensitive can be incorporated into future clinical trials to change in clinical trials for other visual diseases 11,12 and used to most effectively define and compare (e.g., amblyopia, diabetic retinopathy). To date, treatment efficacy. The goal of the REiNS VA is the only visual outcome measure that has been assessed to any major extent in OPG, as well as the Visual Outcomes Committee is to define the only measure that has been shown to be sensitive to best functional outcome measures for future change with treatment. In a large retrospective study, clinical trials of NF1-OPG. The committee 32% of subjects with NF1-OPG experienced an considered the major psychophysical compo- improvement in VA following treatment with chemo- nents of vision (acuity, fields, and color vision), therapy.8 In addition, a decline in VA is the most other ophthalmologic elements affected by common reason to initiate therapy for OPG, and

Table 1 Consensus recommendations for functional outcome measures in NF1 optic pathway glioma clinical trials

Measure Primary endpoint Secondary endpoint Comments

Recommended

Visual acuity Recommended Report in logMAR; account for age-specific acuity norms

Teller acuity Recommended — All ages

HOTV — Recommended Older children (who are able to complete testing)

Visual QOL (CVFQ) — Recommended Validated only for children #8years

Optic disc pallor —— Capture as a contributing variable

Not recommended

Visual fields — Not recommended More information needed

Color vision — Not recommended

Strabismus — Not recommended

Nystagmus — Not recommended

Optic disc swelling — Not recommended

Proptosis — Not recommended

Visual evoked potentials — Not recommended

Optical coherence tomography — Not recommended More information needed

Abbreviations: CVFQ 5 Children’s Visual Function Questionnaire; logMAR 5 logarithm of the minimum angle of resolution; NF1 5 neurofibromatosis type 1; QOL 5 quality of life.

S16 Neurology 81 (Suppl 1) November 19, 2013 other potential markers of functional decline, such as of the test increases with age, such that a higher level visual field (VF) or color vision loss, typically occur of cognition and cooperation is required to complete concurrently with acuity decline.8 As such, VA is the HOTV compared with Lea, and Snellen testing com- best studied and most reliable functional measure of pared with HOTV. This makes testing in children with vision for OPG and other visual diseases. NF1 particularly challenging,asalargeproportionhave How should VA be tested? For the purpose of clinical baseline deficits in attention and/or learning. trials, it is crucial that the selection of testing method One of the challenges in monitoring VA over time is quantifiable so that the magnitude of change can be in children enrolled in a clinical trial is that the pre- accurately measured over time. Qualitative measures, ferred clinical VA testing method may change as the such as “fix and follow” will not always detect VA child gets older. Although there is reasonable correla- changes.13 For example, a 2-year-old whose VA tion of VA results between testing formats, they are changes from 20/40 to 20/100 will still fix and follow. not identical.13 For example, when VA is near normal, There are multiple testing methods available to assess TAC may underestimate VA relative to recognition VA quantitatively. The choice of method depends on acuity.14 In contrast, TAC may overestimate VA com- a child’s age, developmental/cognitive level, and abil- pared with recognition acuity when VA is moderately ity to cooperate. A detailed discussion of VA testing abnormal or worse.15 Hence, transitioning between methods and challenges is beyond the scope of this testing formats may confound the interpretation of report, but the topic has been previously reviewed.13 acuity changes over time. Therefore, we recommend Quantitative testing methods (Teller acuity cards not switching testing formats for subjects during the [TAC]) exist for children as young as 6 months of treatment and follow-up phases of the study. In addi- age and are reliable measures of VA. TAC (figure) is tion, we would limit testing methods to TAC and a preferential looking test that relies on an infant’s HOTV, as these are relatively easy to perform, stan- propensity to redirect his or her gaze toward a visually dardized testing methods exist, and both methods have interesting stimulus (alternating high-contrast black been validated in clinical trials for other pediatric oph- and white lines). VA is quantified by knowing the thalmologic diseases (e.g., retinopathy of prematurity, distance to the stimulus and the width of the smallest amblyopia, cataracts).11,12,16 Of note, it is important to lines the child is able to appreciate. Other methods use a standardized TAC and HOTV testing method at for testing the youngest age group include Cardiff all study sites. acuity cards, which use pictures of varying contrast; To provide consistency from study enrollment however, these have not been studied as widely as through study completion, we suggest the use of TAC an outcome measure for clinical trials. In older chil- as the primary VA endpoint for all subjects regardless dren, testing methods measure the ability to recognize of age, as this is the only visual testing method that all (“recognition acuity”)afigure(e.g.,Leasymbols)or subjects who are old enough for quantitative VA testing letters (e.g., HOTV or Snellen) (figure). The complexity can perform. Of note, in the retrospective study of visual outcomes following chemotherapy, 37.5% of subjects were unable to complete HOTV testing at Figure Visual acuity testing methods the start of treatment.8 In addition, in a study of 127 subjects 10 years and younger with OPG (NF1 and non-NF1), 30.7% could not complete HOTV testing, and the number rose to 67.3% in children younger than 5 years of age.17 Although the committee considered allowing HOTV as a primary outcome measure for those capable of performing it at study entry, we re- jected this for several reasons. First, in a retrospective study8 asmallpercentage(3%)ofchildrenwhowere able to perform HOTV at the start of therapy were unable to perform it successfully at study end and required Lea or TAC testing (data not published). Second, although TAC and HOTV acuities are similar, they are not identical, thus making comparisons between subjects challenging.17 Last, the interval between “lines” on the chart for TAC and HOTV is not equivalent. However, once a subject is old enough to perform testing, we recommend adding HOTV testing as a (A) Teller acuity cards, (B) Lea, (C) HOTV, (D) Snellen. secondary endpoint. Although Teller acuity can be

Neurology 81 (Suppl 1) November 19, 2013 S17 converted to a recognition acuity equivalent, the latter Table 2 Visual acuity equivalents in feet, is a more accurate reflection of how we understand meters, and logMARa VA. Therefore, it is important to capture a recognition acuity measure that can place the Teller acuity Lines on visual acuity chart in context. In addition, these data will facilitate a bet- logMAR Feet Meters ter evaluation of long-term changes in VA as a subject enters adulthood. HOTV testing is preferred because 20.1 20/16 6/5 it can be started at a younger age and is more feasible 0.0 20/20 6/6 in children with NF1-related cognitive or behavioral 0.1 20/25 6/7.5 problems than other recognition acuity testing meth- 0.2 20/32 6/10

ods. Importantly, this recommendation does not pre- 0.3 20/40 6/12 clude testing using an alternate method (e.g., Snellen) 0.4 20/50 6/15 for clinical purposes. 0.5 20/63 6/20 How should VA be reported? Clinically, VA is typically reported as a fraction (e.g., 20/20 in feet, 6/6 in meters), 0.6 20/80 6/24 and change in acuity is usually described by the differ- 0.7 20/100 6/30 ence in the number of lines on the eye chart between 0.8 20/125 6/38

testing sessions. Unfortunately, the difference between 0.9 20/160 6/48

lines can vary not only between testing methods but 1.0 20/200 6/60 also within the same method.13 Therefore, in order to 1.1 20/250 6/75 standardize the quantification of magnitude of change, we recommend that VA be reported using the loga- 1.2 20/320 6/96 rithm of the minimum angle of resolution (logMAR). 1.3 20/400 6/120 For recognition acuity measures, this linear scale is cre- 1.4 20/500 6/150

ated by calculating the base 10 logarithm of 1/(VA 1.5 20/640 6/192

decimal notation [e.g., the decimal equivalent for 1.6 20/800 6/240 20/40 5 0.5]), a practice widely used in clinical ophthalmologic research. Intervals of change between lines Abbreviation: logMAR 5 logarithm of the minimum angle of resolution. on logMAR charts are therefore of equal magnitude a logMAR conversions from Snellen acuities. (table 2). TAC can also be directly converted to log- MAR (logMAR 521 3 log[spatial frequency/30]). It is worth recognizing that classifying VA into categories treatment failure and come off study. In addition, (e.g., good, fair, poor) is problematic as small nonfunc- although reporting vision by the better or worse eye tional changes in VA can result in a change in VA may be useful when reporting long-term outcomes, category. Reporting VA as a continuous measure will its relevance for assessing the effectiveness of a chemo- allow for a more detailed evaluation of visual change therapeutic agent is unclear. Reporting intervals over time. should match those of radiologic reporting. For con- It is equally important to account for the normal sistency, we recommend reporting results at one or development of VA during early childhood. Normal more of the following times: end of therapy and 1-, VA improves with age in young children, thereby 2-, 3-, and/or 5-year follow-up. necessitating different age-based norms (e.g., 20/40 What constitutes visual progressive disease or response? At is normal at age 3 years, 20/20 is normal at age present, there is no validated definition of clinically 6 years).13 Thus, we recommend calculating an age- significant VA change. Several previous OPG studies based VA by comparing all values to normal for age have used a 2-line change (approximately 0.2 log- VA (normal VA for age 2 current VA) and reporting MAR) from baseline, but this has not been validated. the difference in logMAR from normal. However, given that the ophthalmologic literature When reporting study results, we suggest report- reveals a roughly 1-line variation between observers ing both per-subject and per-eye outcomes. The latter and testing sessions,18,19 using a 2-line change is rea- is standard in the ophthalmology literature and is sonable. We recognize the potential risk of decreased important as vision may be affected in only one eye. specificity by using such a narrow definition; how- However, in a subject with a unilateral optic nerve gli- ever, we feel this is offset by increased sensitivity to oma, the unaffected eye should be excluded, as it will early decline in VA. We therefore recommend defin- bias the results. Per-subject reporting is also informa- ing a significant VA change as a 0.2 or greater change tive as illustrated by the following potential scenario: in logMAR. When visual response is detected, it the VA improves in one eye but worsens in the other should be confirmed at a subsequent study visit to during therapy; this subject should be coded as a be considered “durable.”

S18 Neurology 81 (Suppl 1) November 19, 2013 How should ceiling and floor effects be handled? It is crit- Humphrey perimetry). Confrontation testing is not ical to consider ceiling and floor effects for VA when as sensitive as perimetry but can be useful for detecting establishing clinical trial enrollment criteria and ana- large deficits (e.g., quadrantanopia or hemianopia).21 lyzing study data. For example, eyes with normal VA In contrast, the clinical significance of the smaller (20/20 5 0.0 logMAR or better) at baseline cannot changes noted with perimetry for patients with OPG improve and should be eliminated from a study tar- is unclear. Although all VF testing methods require the geting visual response. In contrast, blind eyes cannot patient to be alert and cooperative and to maintain worsen and should be excluded from studies of visual fixation reliably, the testing time for perimetry (5–7 progression-free survival (PFS). Based on our defini- minutes per eye) is longer than for other measures of tion of visual progression or response (60.2 logMAR visual function (e.g., acuity). Given the high incidence or greater change), we recommend a ceiling of 0.2 of learning difficulties and attention deficit disorder in logMAR below normal for age or 0.2 logMAR below children with NF1, there are concerns about the reli- a previous reliably documented VA. We set the floor ability of testing as well as the elevated false-positive at 1.36 logMAR (20/470), which is the VA equiva- and false-negative rates in children younger than lent of the lowest Teller acuity card from which a 10 years of age. In an audit of children with NF1 0.2 logMAR decline can be measured with good reli- up to 7 years of age, none of the children was mature ability (using a standard testing distance of 55 cm). enough to reliably complete VF testing.22 Based on these considerations, we recommend that In the OPG literature, most studies do not report one eye must be evaluable (0.2 logMAR below nor- VF, do so only in a small subset of subjects, or do not mal for age or below a previous reliably documented provide within-subjects comparisons. In addition, de- VA 2 1.36 logMAR) in order to enroll in a thera- tails regarding VF testing method or consistency with peutic OPG trial. When analyzing results, if the study quantification are often lacking. Several studies reveal endpoint is best visual response, then eyes with VA at that VF deficits are usually (89%–100%) associated the ceiling should be excluded. If the study endpoint with concurrent VA deficits,8,23 VF change in the is visual PFS, then eyes with VA at the floor should be absence of VA change is rarely a treatment indica- excluded in the analysis. tion,8 and VF outcome mostly mirrors VA outcome How often should VA be monitored while on study? At following treatment.8 present, no evidence exists to recommend an ideal In summary, given the concerns about the reliabil- monitoring interval to determine visual progression ity of VF testing in this patient population, the lack of or response in a clinical trial. Thus, we recommend adequate data from prior studies (especially compared monitoring on the same schedule as imaging out- with VA), and the fact that VF deficits are usually comes, which is typically every 3 months while on associated with concurrent VA deficits, the committee treatment. Following completion of treatment, we does not endorse VF as a primary outcome measure for recommend monitoring at 3, 6, 12, 18, 24, 30, 36, OPG clinical trials. A more thorough evaluation of VF 48, and 60 months. in NF1-OPG is required before routine inclusion as a What if the examination is unreliable due to poor secondary outcome measure can be recommended. cooperation or a change in VA is detected or suspected? If Color vision. Standard color vision testing (e.g., Ishihara) the results of a VA evaluation are in doubt because requires cooperation and the ability to read numbers or of poor effort or cooperation, testing should be identify shapes; thus, most very young children with repeated in 1 to 2 weeks. If the result is still unre- NF1-OPG are unable to complete testing.22 Color liable, then no data should be entered for that visit. vision data are rarely collected,24 and changes in color If the clinician is absolutely certain the VA change vision over time are rarely reported in OPG studies. is not related to effort/cooperation, then a repeat Testing color vision may be helpful in differentiating examination is not required. In most instances, how- the cause of VA loss. In this respect, color vision is ever, the exam will need to be repeated. If VA loss is usually spared in amblyopia or refractive error, whereas observed, it is crucial to exclude refractive error, ambly- color vision loss typically accompanies the VA loss due opia, or other non-OPG-related causes. to OPG.1 Therefore, color vision loss is unlikely to provide additional information about disease progres- OTHER POSSIBLE FUNCTIONAL ENDPOINTS Visual sion relative to VA. In summary, while color vision fields. VF deficits may occur in association with OPG; testing may be a good adjunct measure in clinical trials, therefore, recommendations for testing visual function further study is needed before it can be recommended in children with NF1 have included VF testing during for routine inclusion. selected ophthalmology evaluations.1,20 There is a range of methods for VF testing, including simple confron- Strabismus. Strabismus (ocular misalignment) is mea- tation (testing the ability to see fingers in all 4 quad- sured in prism diopters, but the variability in meas- rants) and computerized techniques (Goldmann or urements may be as much as 6 diopters, and it may

Neurology 81 (Suppl 1) November 19, 2013 S19 be difficult to quantify reliably in uncooperative chil- in those with vision loss. In addition, the development dren.25 Although eye deviation in OPG may be due of disc pallor can lag behind the appearance of a VA to optic nerve enlargement with downward displace- deficit and vice versa. One study suggests that optic ment of the globe, it is usually secondary to VA loss in disc pallor at the start of chemotherapy may be associ- the affected eye (i.e., sensory strabismus).1 No correla- ated with worse VA outcomes; however, change in disc tion has been reported between the amount of VA loss pallor over time is not a useful marker, as it almost and the occurrence or severity of strabismus. In addi- never improves.8 tion, strabismus is rarely commented on or followed In external compressive tumors of the optic chiasm longitudinally in large OPG series, and its incidence is (e.g., pituitary adenoma or craniopharyngioma), disc much lower than that of VA loss.8,26–28 Therefore, at pallor correlates with the presence of decreased VA present strabismus is not recommended as an outcome but not the degree of vision loss.29–31 However, the measure to follow OPGs. predictive value of pallor for VA recovery following tumor decompression is variable, although it appears Nystagmus. Nystagmus (rhythmic oscillation of the that those with “mild” pallor may be more likely to eyes) can be a presenting sign of an OPG, typically have some recovery of vision.32,33 This observation is one located in the optic chiasm/hypothalamus. As also supported by optical coherence tomography stud- with strabismus, nystagmus in OPG is usually second- ies of the retinal nerve fiber layer in this population.34 1 ary to VA loss in the affected eye(s). Few studies report The degree of disc pallor has also been suggested to be on nystagmus, but in those that do the incidence is low an important factor in VA outcome for patients with – 8,27,28 (2% 19%). It is difficult to quantify nystagmus OPG5 and those with atrophy from any cause35; how- without sophisticated eye movement recordings, and ever, in these studies, the degree of pallor was deter- there does not appear to be a correlation between con- mined subjectively (which is affected by the degree of tinued VA decline and the severity of the nystagmus. pigmentation of the fundus) or by using photographic Given these factors, the committee does not recom- slides (in which the color of the optic disc depends on mend following nystagmus as an outcome measure the length of exposure). for OPG. In summary, monitoring changes in disc pallor over time during a clinical trial does not appear useful, as it Optic disc swelling. Optic disc swelling is the visible elevation of the optic disc with blurring of the disc rarely improves. Disc pallor is likely associated with VA margin seen on fundus exam. Its incidence in OPG loss, but not universally. Although the degree of disc varies widely (up to 21%) in the few studies that pallor may be the more relevant feature, at present report on optic disc swelling.8,26,28 It appears to be there is no accepted scale to grade pallor or data indicat- more commonly associated with tumor involvement ing that it can be measured reliably, even using photo- of the optic nerve.28 Disc swelling from chiasmal graphs. However, because of the correlation between lesions more frequently reflects elevated intracranial baseline disc pallor and VA outcomes in treated sub- pressure from obstruction of CSF flow. Although disc jects as well as the possible implication that pallor swelling may be associated with a change in the size of may be an indicator of preexisting damage that heralds 5,8 the OPG on MRI scan, it is not always associated subsequent vision loss, we recommend capturing disc with demonstrable VA loss. In addition, optic disc pallor (present or not) to define its role as a contributing swelling is not predictive of VA outcome, as it improves variable or correlative marker in future OPG trials. in almost all subjects (91%) following chemotherapy.8 For these reasons, it is not recommended as an outcome Proptosis. There are scant objective data on measuring measure to follow OPGs. proptosis in orbital tumors. Measurements can be performed by exophthalmometry,36 and normative Optic disc pallor. Optic disc pallor corresponds to atro- measurements based on age have been reported in phy of the optic nerve fibers and can reflect damage children.37,38 Although there is interobserver reliability anywhere along the optic pathway from the retina to of exophthalmometry in healthy adults with and with- the lateral geniculate nucleus. It is easy to visualize out Graves disease,39 there is no known large study on fundus exam, is usually commented on in OPG examining exophthalmometry in children with orbital studies, and is present in almost half of OPG cases tumors. In contrast, proptosis has been measured suc- (combined data of 18 studies). Unfortunately, it is cessfully and serially using MRI in children with optic not clear whether disc pallor is associated with vision nerve gliomas40 and may be a more accurate method of loss, given that few studies have attempted to evaluate measuring the degree of proptosis; however, a recent this relationship, often with small sample sizes and study demonstrated that improvement in proptosis did mixtures of NF1/sporadic OPG and treated/untreated not correlate with tumor shrinkage.41 Most impor- OPG. Optic disc pallor often occurs in patients with tantly, it is unclear how to quantify the functional OPG without a VA or VF deficit and may be absent impact of a change in proptosis. In addition, patients

S20 Neurology 81 (Suppl 1) November 19, 2013 with proptosis comprise a minority of subjects enrolled emerged as important measures for use in clinical in OPG trials. Further study will be required before treatment trials. VA loss has been reported to affect considering the inclusion of routine proptosis measure- markedly an individual’s employment and overall ments in future therapeutic studies. QOL.9,10 To evaluate the direct impact of vision loss on particular QOL domains, vision-specific QOL Visual evoked potentials. Visual evoked potentials instruments have been developed for adults and were (VEPs) are an electrophysiologic test believed to profound to correlate with the degree of visual impair- vide a functional measure of visual pathway integrity. ment.56–58 Visual ability and QOL measures that Although VEP testing may detect OPG with some assess the impact of vision loss in children have been 42–46 sensitivity, some patients with NF1 have abnormal examined in a variety of pediatric eye diseases, with 47 VEP testing despite no evidence of glioma. Of greater most designed to evaluate children between 8 and concern is the poor diagnostic sensitivity of VEP for 18 years of age.59–63 Using the review process developed 48 VA loss and the poor correlation of VEP changes over by the REiNS Patient-Reported Outcomes Subcom- 49,50 time with VA changes and response to treatment. mittee (see Wolters et al., this supplement), we Several other issues limit the utility of VEP for OPG reviewed the available pediatric questionnaires. Of clinical trials, including the challenge of testing young these, 2 examined visual ability rather than vision- children because of the level of cooperation required, specific QOL.62,63 Two vision-specific QOL meas- the lack of standardization of testing methods, the ures have been developed for children,59,60 although absence of a validated definition of the amount of the Children’sVisualFunctionQuestionnaire(CVFQ)59 “ ” change that defines worsening in longitudinal studies, is the only instrument designed to evaluate children the lack of universal availability of the equipment, and 8 years of age and younger, the time during which the variability in measures using different equipment. most patients with NF1-OPG become symptomatic. Therefore, the committee does not recommend the To date, no studies have been published that evaluate routine inclusion of VEP testing for OPG clinical trials. the impact of OPG-related vision loss on vision- Optical coherence tomography. The axons of the retinal specific QOL in children. The inclusion of a vision- ganglion cells, termed the retinal nerve fiber layer specific QOL measure in NF1-OPG clinical trials is (RNFL), combine to form the pregeniculate portion complicated by a number of factors, including the of the afferent visual pathway (i.e., optic nerve, chi- potential differential impact of VA vs VF loss, the asm, and tracts). RNFL thickness, a structural marker use of parent proxy reporting, the wide age range of of visual pathway integrity, can be measured using subjects enrolled, and the relevance of the vision loss optical coherence tomography (OCT). Thinning of based on age. For example, moderate vision loss may the RNFL correlates with VA and/or VF deficits in have only a modest impact on QOL for a 3-year-old, patients with optic neuritis and multiple sclerosis whereas in an adolescent the same degree of vision loss (MS).51,52 Studies also suggest that significant RNFL may result in the inability to drive a motor vehicle, thinning predicts persistence of visual deficits over which might result in a more profound effect on time for both MS and compressive tumors of the QOL. Additionally, it is unclear whether and how optic chiasm.34,53 In addition, decreased RNFL thick- the known developmental and behavioral complica- ness correlated with visual loss (VA and/or VF) in a tions of NF1 might influence the accuracy and rele- cross-sectional study of children (6–21 years of age) vance of QOL measures. Therefore, the committee with OPG.54 This study is currently being replicated does not recommend a vision-specific QOL measure in children with OPG younger than 6 years using as a primary outcome at this time, although the CVFQ portable OCT equipment (necessary for evaluating could be considered as a secondary outcome measure young children).55 Ultimately, longitudinal studies in children 8 years of age and younger. Ultimately, will be required to determine whether a decrease in development of a NF1-OPG-specific QOL measure RNFL thickness is predictive of future vision loss and or adapting the CVFQ to include domains relevant whether changes in RNFL thickness over time correlate to all age groups may be helpful and is currently being with changes in visual function. In addition, portable considered. OCT equipment is not yet widely available, RNFL measurements vary between different OCT machines, REiNS RECOMMENDATIONS VA should be the and the reliability of RNFL measures between centers main functional outcome measure in clinical trials using the same equipment is unknown. Hence, routine of children with NF1-OPG. The use of quantitative inclusion in clinical trials for OPG cannot be recom- testing methods is essential, and the testing format mended at this time. should not be changed during the study. To that end, we recommend the use of TAC as the primary Visual quality of life. Patient-reported outcomes, spe- VA endpoint and HOTV as a secondary endpoint cifically those assessing quality of life (QOL), have once subjects are old enough. Results should be

Neurology 81 (Suppl 1) November 19, 2013 S21 reported in logMAR, while taking into account the (U.S. Patent No. 5,859,195), for which he receives royalties annually, and a acuity age-specific norms. The optic disc should be patent for Neurofibromin Pathway Modulators (U.S. Patent No. 8,101,606). He has received honoraria for invited lectureships at UCSD, assessed for pallor, as this appears to be a contributory Johns Hopkins University, Memorial Sloan-Kettering Cancer Center, Cleve- variable that may affect the interpretation of VA land Clinic Foundation, University of Minnesota, Biomarin, MD Anderson change over time. Given the importance of capturing Cancer Center, University of Toronto, Dana Farber Cancer Institute, and the University of Chicago. He receives research support from the National patient-reported outcomes in clinical trials, the com- Brain Tumor Society, James S. McDonnell Foundation, Department of mittee endorses collecting visual QOL using the Defense, National Cancer Institute (grants CA136573, CA141549, and CVFQ as a secondary endpoint, as this is currently CA160882), Children’s Discovery Institute (grant MC-II-2012-212), and the best available measure. Collectively, the imple- the NIH (grants NS065547 and NS072916). R. Listernick serves as an editorial board member of Pediatric Annals. He received honoraria for oral mentation of these endpoints in future clinical trials presentations from Children’s Hospital of Colorado and American Academy will facilitate the evaluation of potential promising of Pediatrics. S. Martin received funding for a trip from the Children’s agents for the treatment of NF1-OPG. Tumor Foundation. N. Ullrich receives funding from the Department of Defense (W81XWH-05-1-0615), the NIH (NCT00879034), the National Cancer Foundation Children’s Oncology Group, and the Children’s Tumor AUTHOR CONTRIBUTIONS Foundation. She holds patents for a method of diagnosing and treating MJ Fisher: drafting the manuscript, study concept, interpretation of data. gliomas (US 5905027, 6028174, 6319891, 6429187, and 6870029), for RA Avery: revising the manuscript for content, study concept, interpreta- which she receives royalty payments from the University of Alabama at tion of data. JC Allen: revising the manuscript for content, study concept, Birmingham Research Foundation. She also receives royalties from UpTo- interpretation of data. SL Ardern-Holmes: revising the manuscript for Date for the publication of “The “choking game” and other strangulation content, study concept, interpretation of data. LT Bilaniuk: revising the activities in children and adolescents.” She has received travel expenses and/or manuscript for content, study concept, interpretation of data. RE Ferner: honoraria for lectures or educational activities not funded by industry, and revising the manuscript for content, study concept, interpretation of data. has served as an expert witness for O’Connor, O’Connor, Bresee & First and DH Gutmann: revising the manuscript for content, study concept, inter- Bays, Lung, Rose & Holma. G. Liu has consulted for Ipsen and received pretation of data. R Listernick: revising the manuscript for content, study book royalties from Elsevier. Go to Neurology.org for full disclosures. concept, interpretation of data. S Martin: revising the manuscript for content, study concept, interpretation of data. NJ Ullrich: revising the manuscript for content, study concept, interpretation of data. GT Liu: revising Received May 17, 2013. Accepted in final form August 13, 2013. the manuscript for content, study concept, interpretation of data. REFERENCES ACKNOWLEDGMENT 1. Listernick R, Ferner RE, Liu GT, Gutmann DH. Optic pathway gliomas in neurofibromatosis-1: controversies and The committee acknowledges Vanessa Merker, BS, Massachusetts General – Hospital; Mark Kieran, MD, PhD, Boston Children’s Hospital; and recommendations. Ann Neurol 2007;61:189 198. Graham Quinn, MD, The Children’s Hospital of Philadelphia for their 2. Packer RJ, Ater J, Allen J, et al. Carboplatin and vincristine helpful input as well as Scott Plotkin, MD, PhD, Massachusetts General chemotherapy for children with newly diagnosed progressive Hospital, Brigitte Widemann MD, National Cancer Institute, and the low-grade gliomas. J Neurosurg 1997;86:747–754. other members of the REiNS International Collaboration. The committee 3. Ater J, Holmes E, Zhou T, et al. Abstracts from the thir- also acknowledges the helpful input of the representatives of the Interna- teenth international symposium on pediatric neuro-oncology: tional Society of Pediatric Oncology Low Grade Glioma committee results of COG protocol A9952- a randomized phase 3 study (Joseph Abbott, Silva Atamian, Catherine Cassiman, Maurizio Clementi, of two chemotherapy regimens for incompletely resected Pablo Hernáiz Driever, Chris Hammond, Darren Hargrave, Kamilla low-grade glioma in young children. Neuro Oncol 2008; Rothe Nissen, Enrico Opocher, Susan Picton, Arun Reginald, Astrid 10:451. Sehested, Ian Simmons, Irene Slavc, David Walker). 4. Prados MD, Edwards MS, Rabbitt J, Lamborn K, Davis RL, Levin VA. Treatment of pediatric low-grade STUDY FUNDING gliomas with a nitrosourea-based multiagent chemotherapy No targeted funding reported. regimen. J Neurooncol 1997;32:235–241. 5. Campagna M, Opocher E, Viscardi E, et al. Optic path- DISCLOSURE way glioma: long-term visual outcome in children without M. Fisher received reimbursement from the Children’s Tumor Foundation neurofibromatosis type-1. Pediatr Blood Cancer 2010;55: to attend their annual Neurofibromatosis Conference, is funded by the 1083–1088. Department of Defense (W81XWH-12-1-0155, W81XWH-05-1-0615), 6. Moreno L, Bautista F, Ashley S, Duncan C, Zacharoulis S. Thrasher Research Fund, the Children’s Tumor Foundation, and Sarcoma Does chemotherapy affect the visual outcome in children Alliance for Research through Collaboration, and received research support from the Pediatric Low Grade Astrocytoma Foundation, Bayer, Children’s with optic pathway glioma? A systematic review of the Discovery Institute, NIH (NR009651-01), and the Department of evidence. Eur J Cancer 2010;46:2253–2259. Defense (W81XWH-08-1-0051). R. Avery is funded by NIH grants 7. Shofty B, Ben-Sira L, Freedman S, et al. Visual outcome K23-EY022673 and UL1RR031988/UL1TR000075, and received research following chemotherapy for progressive optic pathway support from the Gilbert Family Neurofibromatosis Institute. J. Allen reports gliomas. Pediatr Blood Cancer 2011;57:481–485. no disclosures. S. Ardern-Holmes served on a scientific advisory board for 8. Fisher MJ, Loguidice M, Gutmann DH, et al. Visual out- Novartis Pharmaceuticals Australia, received funding for a trip from Novartis comes in children with neurofibromatosis type 1-associated ’ Pharmaceuticals Australia, and receives research support from The Children s optic pathway glioma following chemotherapy: a multi- Tumor Foundation of Australia. L. Bilaniuk receives research support from center retrospective analysis. Neuro Oncol 2012;14: the NICHD #UO1HD068541-01. R. Ferner received funding for travel 790–797. from the Children’s Tumor Foundation and the European Neurofibroma- tosis Association. She receives royalties from Springer for the book Neuro- 9. Rahi JS, Cumberland PM, Peckham CS. Visual function fibromatoses in Clinical Practice. D. Gutmann serves on the scientific advisory in working-age adults: early life influences and associations board of the Brain Tumor Funder’s Collaborative and the editorial board of with health and social outcomes. Ophthalmology 2009; Experimental Neurology. He holds the patent on the neurofibromatosis gene 116:1866–1871.

S22 Neurology 81 (Suppl 1) November 19, 2013 10. Rahi JS, Cumberland PM, Peckham CS. Visual impair- 27. Thiagalingam S, Flaherty M, Billson F, North K. Neuro- ment and vision-related quality of life in working-age fibromatosis type 1 and optic pathway gliomas: follow-up adults: findings in the 1958 British birth cohort. Ophthal- of 54 patients. Ophthalmology 2004;111:568–577. mology 2009;116:270–274. 28. Tow SL, Chandela S, Miller NR, Avellino AM. Long-term 11. Dobson V, Quinn GE, Biglan AW, Tung B, Flynn JT, outcome in children with gliomas of the anterior visual Palmer EA. Acuity card assessment of visual function in pathway. Pediatr Neurol 2003;28:262–270. the cryotherapy for retinopathy of prematurity trial. Invest 29. Hollenhorst RW, Younge BR. Ocular manifestations pro- Ophthalmol Vis Sci 1990;31:1702–1708. duced by adenomas of the pituitary gland: analysis of 12. Moke PS, Turpin AH, Beck RW, et al. Computerized 1,000 cases. In: Kohler PO, Ross GT, eds. Diagnosis method of visual acuity testing: adaptation of the ambly- and Treatment of Pituitary Tumors. Amsterdam: Excerpta opia treatment study visual acuity testing protocol. Am J Medica-American Elsevier; 1972:53–64. Ophthalmol 2001;132:903–909. 30. Kennedy HB, Smith RJ. Eye signs in craniopharyngioma. 13. Avery RA, Ferner RE, Listernick R, Fisher MJ, Br J Ophthalmol 1975;59:689–695. Gutmann DH, Liu GT. Visual acuity in children with 31. Melen O. Neuro-ophthalmologic features of pituitary tu- low grade gliomas of the visual pathway: implications for mors. Endocrinol Metab Clin North Am 1987;16:585–608. patient care and clinical research. J Neurooncol 2012;110: 32. Cohen AR, Cooper PR, Kupersmith MJ, Flamm ES, 1–7. Ransohoff J. Visual recovery after transsphenoidal removal 14. Dobson V, Quinn GE, Tung B, Palmer EA, Reynolds JD. of pituitary adenomas. Neurosurgery 1985;17:446–452. Comparison of recognition and grating acuities in very- 33. Lennerstrand G. Visual recovery after treatment for pituitary low-birth-weight children with and without retinal residua adenoma. Acta Ophthalmol (Copenh) 1983;61:1104–1117. of retinopathy of prematurity. Cryotherapy for Retinopathy 34. Danesh-Meyer HV, Papchenko T, Savino PJ, Law A, of Prematurity Cooperative Group. Invest Ophthalmol Vis Evans J, Gamble GD. In vivo retinal nerve fiber layer Sci 1995;36:692–702. thickness measured by optical coherence tomography pre- 15. Kushner BJ, Lucchese NJ, Morton GV. Grating visual dicts visual recovery after surgery for parachiasmal tumors. acuity with Teller cards compared with Snellen visual acuity Invest Ophthalmol Vis Sci 2008;49:1879–1885. in literate patients. Arch Ophthalmol 1995;113:485–493. 35. DeWitt CA, Johnson LN, Schoenleber DB, Hainsworth DP, 16. Lambert SR, Buckley EG, Drews-Botsch C, et al. The Madsen RW. Visual function in patients with optic nerve infant aphakia treatment study: design and clinical meas- pallor (optic atrophy). J Natl Med Assoc 2003;95:394–397. ures at enrollment. Arch Ophthalmol 2010;128:21–27. 36. Hertel E, Simonsz HJ. A simple exophthalmometer. Stra- 17. Avery RA, Bouffet E, Packer RJ, Reginald A. Feasibility bismus 2008;16:89–91. and comparison of visual acuity testing methods in chil- 37. Dijkstal JM, Bothun ED, Harrison AR, Lee MS. Normal dren with neurofibromatosis type 1 and/or optic pathway exophthalmometry measurements in a United States pediat- gliomas. Invest Ophthalmol Vis Sci 2013;54:1034–1038. ric population. Ophthal Plast Reconstr Surg 2012;28:54–56. 18. Getz LM, Dobson V, Luna B, Mash C. Interobserver 38. Nucci P, Brancato R, Bandello F, Alfarano R, Bianchi S. reliability of the Teller Acuity Card procedure in pediatric Normal exophthalmometric values in children. Am J patients. Invest Ophthalmol Vis Sci 1996;37:180–187. Ophthalmol 1989;108:582–584. 19. Harvey EM, Dobson V, Tung B, Quinn GE, Hardy RJ. 39. Mourits MP, Lombardo SH, van der Sluijs FA, Fenton S. Interobserver agreement for grating acuity and letter acuity Reliability of exophthalmos measurement and the exophthal- assessment in 1- to 5.5-year-olds with severe retinopathy of mometry value distribution in a healthy Dutch population prematurity. Invest Ophthalmol Vis Sci 1999;40:1565–1576. and in Graves’ patients. An exploratory study. Orbit 2004; 20. Ferner RE, Huson SM, Thomas N, et al. Guidelines for 23:161–168. the diagnosis and management of individuals with neuro- 40. Diaz RJ, Laughlin S, Nicolin G, Buncic JR, Bouffet E, fibromatosis 1. J Med Genet 2007;44:81–88. Bartels U. Assessment of chemotherapeutic response in 21. Kerr NM, Chew SS, Eady EK, Gamble GD, Danesh- children with proptosis due to optic nerve glioma. Childs Meyer HV. Diagnostic accuracy of confrontation visual Nerv Syst 2008;24:707–712. field tests. Neurology 2010;74:1184–1190. 41. Nguyen-Phuc AY, Khrichenko D, Feygin T, Fisher MJ, 22. Pilling RF, Lloyd IC, Huson S. Utility of optic pathway Liu GT. Abstracts from the 65th annual meeting of the glioma screening in young children with neurofibromatosis American Academy of Neurology: proptosis in optic pathway type I: questions generated by a clinical audit. Eye (Lond) gliomas associated with neurofibromatosis: response to che- 2010;24:1603–1605. motherapy. Neurology 2013 (http://www.abstracts2view. 23. Sigorini M, Zuccoli G, Ferrozzi F, et al. Magnetic resonance com/aan/view.php?nu5AAN13L_P06.004). findings and ophthalmologic abnormalities are correlated in 42. Chang BC, Mirabella G, Yagev R, et al. Screening and patients with neurofibromatosis type 1 (NF1). Am J Med diagnosis of optic pathway gliomas in children with neu- Genet 2000;93:269–272. rofibromatosis type 1 by using sweep visual evoked poten- 24. Dalla Via P, Opocher E, Pinello ML, et al. Visual outcome tials. Invest Ophthalmol Vis Sci 2007;48:2895–2902. of a cohort of children with neurofibromatosis type 1 and 43. Jabbari B, Maitland CG, Morris LM, Morales J, optic pathway glioma followed by a pediatric neuro-oncology Gunderson CH. The value of visual evoked potential as program. Neuro Oncol 2007;9:430–437. a screening test in neurofibromatosis. Arch Neurol 1985; 25. Liu GT, Volpe NJ, Galetta SL. Neuro-Ophthalmology: 42:1072–1074. Diagnosis and Management, 2nd ed. London: Saunders 44. Lund AM, Skovby F. Optic gliomas in children with neu- Elsevier; 2010. rofibromatosis type 1. Eur J Pediatr 1991;150:835–838. 26. Nicolin G, Parkin P, Mabbott D, et al. Natural history 45. North K, Cochineas C, Tang E, Fagan E. Optic gliomas in and outcome of optic pathway gliomas in children. Pediatr neurofibromatosis type 1: role of visual evoked potentials. Blood Cancer 2009;53:1231–1237. Pediatr Neurol 1994;10:117–123.

Neurology 81 (Suppl 1) November 19, 2013 S23 46. Wolsey DH, Larson SA, Creel D, Hoffman R. Can screen- during sedation detects visual acuity and visual field loss ing for optic nerve gliomas in patients with neurofibromatosis in young children with optic pathway gliomas. Neuro type I be performed with visual-evoked potential testing? Oncol 2012;14:i69. JAAPOS2006;10:307–311. 56. Cole SR, Beck RW, Moke PS, Gal RL, Long DT. The 47. Iannaccone A, McCluney RA, Brewer VR, et al. Visual National Eye Institute Visual Function Questionnaire: evoked potentials in children with neurofibromatosis type experience of the ONTT. Optic neuritis treatment trial. 1. Doc Ophthalmol 2002;105:63–81. Invest Ophthalmol Vis Sci 2000;41:1017–1021. 48. Ng Y, North KN. Visual-evoked potentials in the assess- 57. Jampel HD, Schwartz A, Pollack I, Abrams D, Weiss H, ment of optic gliomas. Pediatr Neurol 2001;24:44–48. Miller R. Glaucoma patients’ assessment of their visual func- 49. Falsini B, Ziccardi L, Lazzareschi I, et al. Longitudinal tion and quality of life. J Glaucoma 2002;11:154–163. assessment of childhood optic gliomas: relationship 58. Mowry EM, Loguidice MJ, Daniels AB, et al. Vision between flicker visual evoked potentials and magnetic res- related quality of life in multiple sclerosis: correlation with onance imaging findings. J Neurooncol 2008;88:87–96. new measures of low and high contrast letter acuity. 50. Kelly JP, Leary S, Khanna P, Weiss AH. Longitudinal J Neurol Neurosurg Psychiatry 2009;80:767–772. measures of visual function, tumor volume, and prediction 59. Birch EE, Cheng CS, Felius J. Validity and reliability of of visual outcomes after treatment of optic pathway glio- the Children’s Visual Function Questionnaire (CVFQ). mas. Ophthalmology 2012;119:1231–1237. J AAPOS 2007;11:473–479. 51. Cheng H, Laron M, Schiffman JS, Tang RA, Frishman LJ. 60. Cochrane GM, Marella M, Keeffe JE, Lamoureux EL. The The relationship between visual field and retinal nerve Impact of Vision Impairment for Children (IVI_C): vali- fiber layer measurements in patients with multiple sclero- dation of a vision-specific pediatric quality-of-life question- sis. Invest Ophthalmol Vis Sci 2007;48:5798–5805. naire using Rasch analysis. Invest Ophthalmol Vis Sci 52. Talman LS, Bisker ER, Sackel DJ, et al. Longitudinal 2011;52:1632–1640. study of vision and retinal nerve fiber layer thickness in 61. Felius J, Stager DR Sr, Berry PM, et al. Development of an multiple sclerosis. Ann Neurol 2010;67:749–760. instrument to assess vision-related quality of life in young 53. Costello F, Hodge W, Pan YI, Eggenberger E, Coupland S, children. Am J Ophthalmol 2004;138:362–372. Kardon RH. Tracking retinal nerve fiber layer loss after 62. Gothwal VK, Lovie-Kitchin JE, Nutheti R. The develop- optic neuritis: a prospective study using optical coherence ment of the LV Prasad-Functional Vision Questionnaire: a tomography. Mult Scler 2008;14:893–905. measure of functional vision performance of visually 54. Avery RA, Liu GT, Fisher MJ, et al. Retinal nerve fiber impaired children. Invest Ophthalmol Vis Sci 2003;44: layer thickness in children with optic pathway gliomas. Am 4131–4139. J Ophthalmol 2011;151:542–549 e2. 63. Khadka J, Ryan B, Margrain TH, Court H, Woodhouse JM. 55. Avery R, Hwang E, Acosta M, et al. Abstracts from the Development of the 25-item Cardiff Visual Ability Question- fifteenth international symposium on pediatric neuro- naire for Children (CVAQC). Br J Ophthalmol 2010;94: oncology: Hand-held optical coherence tomography 730–735.

S24 Neurology 81 (Suppl 1) November 19, 2013 Topical Review Article

Journal of Child Neurology 2017, Vol. 32(1) 9-22 ª The Author(s) 2016 Neurofibromatosis Type 2: Presentation, Reprints and permission: sagepub.com/journalsPermissions.nav Major Complications, and Management, DOI: 10.1177/0883073816666736 With a Focus on the Pediatric Age Group journals.sagepub.com/home/jcn

Simone Ardern-Holmes, MBChB1, Gemma Fisher, MBChB2, and Kathryn North, MBBS, MD, FRACP3

Abstract Neurofibromatosis type 2 (NF2) is a rare autosomal dominant disorder (incidence 1:33 000-40 000) characterized by formation of central nervous system tumors, due to mutation in the NF2 gene on chromosome 22q12. Vestibular schwannomas are the hallmark lesion, affecting 95% of individuals and typically occur bilaterally. Schwannomas commonly occur on other nerves intracranially and in the spinal compartment, along with meningiomas, ependymomas, and gliomas. Although histologically benign, tumors are associated with significant morbidity due to multiple problems including hearing and vision loss, gait abnormalities, paralysis, pain, and seizures. Risk of early mortality from brainstem compression and other complications is significant. Severity of disease is higher when NF2 presents during childhood. Children have a more variable presentation, which can be associated with significant delays in recognition of the condition. Careful examination of the skin and eyes can identify important clinical signs of NF2 during childhood, allowing timely initiation of disease-specific surveillance and treatment. Monitoring for complications comprises clinical evaluation, along with functional testing including audiology and serial neuroimaging, which together inform decisions regarding treatment. Evidence for disease-specific medical treatment options is increasing, nevertheless most patients will benefit from multimodal treatment including surgery during their lifetime. Patient enrolment in international natural history and treatment trials offers the best opportunity to accelerate our understanding of the complications and optimal treatment of NF2, with a view to improving outcomes for all affected individuals.

Keywords neurofibromatosis type 2, vestibular schwannoma, tumors, presentation, complications, management, treatment, children, pediatric

Received January 29, 2016. Received revised June 22, 2016. Accepted for publication July 26, 2016.

Neurofibromatosis type 2 (NF2) is an autosomal dominant Diagnostic Criteria disorder caused by mutations to the NF2 tumor suppressor The diagnosis of NF2 based on clinical criteria has been refined gene, characterized by multiple nonmalignant nervous sys- over time, reflecting the typical presentation of adults with tem tumors, including schwannomas, meningiomas, ependy- symptoms of vestibular schwannoma (Table 1).6-8 However, momas and gliomas, with bilateral vestibular schwannomas these criteria are less helpful in children who frequently present being a classical feature. Ocular and cutaneousmanifesta- with other symptoms and signs of NF2, and for whom tions also occur. Incidence is estimated at 1 in 33 000-40 000 and prevalence 1 in 100 000.1 The condition is typically diagnosed at age 20-30 years, but features are often present 1 for many years before the diagnosis is made in both sporadic TY Nelson Department of Neurology and Neurosurgery, Children’s Hospital 2-4 at Westmead, Westmead, New South Wales, Australia cases and in those with a family history. About 10% of 2 Sydney Children’s Hospital, New South Wales, Australia patients present before the age of 10 years, and 18% before 3 Murdoch Children’s Research Institute, Royal Children’s Hospital, Parkville, the age of 15 years, with a greater diversity of clinical Victoria, Australia problems than seen in adults,andoftenwithincreased severity.5 In this review we explore the presentation and Corresponding Author: Simone Ardern-Holmes, MBChB, TY Nelson Department of Neurology and clinical course of NF2 with particular reference to children Neurosurgery, Children’s Hospital at Westmead, Hawkesbury Rd, and adolescents, and a view to improving outcomes for all Westmead, NSW 2145, Australia. affected individuals. Email: [email protected] 10 Journal of Child Neurology 32(1)

Table 1. Clinical Diagnostic Criteria for Neurofibromatosis Type 2. mosaicism may result, such that only a proportion of cells carry the mutation. It is estimated that 25% of sporadic mutations are Additional features needed mosaic.16 The transmission rate depends on the degree of mosai- Primary finding for diagnosis cism. For children of patients with a de novo mutation, the Bilateral vestibular schwannomas None needed transmission rate is 50%, because all the child’s cells contain First degree relative with NF2 Unilateral vestibular schwannoma the mutation. However, the transmission rate may be lower in de OR novo patients, as germ cells may not contain the mutation.17 Any 2 other NF2-associated Identification of a mutation in the NF2 gene is possible in lesions: over 90% of familial cases,8 and 80-85% of individuals with Meningioma, schwannoma, glioma, 18 neurofibroma, cataract sporadic mutations, confirming the diagnosis when present in 19 Unilateral vestibular Any 2 other NF2-associated both tumor and blood. In mutation-negative individuals, con- schwannoma lesions: firmation of the clinical diagnosis is possible through careful Meningioma, schwannoma, glioma, follow-up over time. neurofibroma, cataract In children presenting early with a more severe clinical Multiple meningiomas Unilateral vestibular schwannoma course, mosaicism is less likely and consequently the mutation OR Any 2 other NF2-associated detection rate is higher. One study exploring the utility of lesions: mutation testing to screen for NF2 in patients presenting with Schwannoma, glioma, unilateral vestibular schwannomas showed that this is justified neurofibroma, cataract in those presenting <20 years of age 83% of patients presenting under the age of 20 with a unilateral vestibular schwannomas Source: Modified from Evans7 and Asthagiri et al.8 Abbreviation: NF2, neurofibromatosis type 2. were found to have a detectable NF2 mutation compared to 7.7% when looking at all ages.20 In children of a parent with NF2, identification of a mutation vestibular tumors may be too small to appreciate on initial has a major impact on the further screening of that individual.21 neuroimaging. Examination of the skin and eyes often yields In sporadic cases, failure to identify a mutation does not obvi- important diagnostic clues during childhood, and as such is of ate the need for ongoing surveillance, due to the phenomenon fundamental importance in suspected cases. Parents of children of mosaicism, or possibly presence of mutations in intronic suspected of having NF2 should also be assessed carefully for regions, promotor mutations, or large multiexonic deletions.4 symptoms and signs of NF2. Time to diagnosis is highly variable and is often prolonged Genotype-Phenotype Correlation despite symptoms presenting in childhood. A recent report cited time to diagnosis in subgroups of adults and children at Missense mutations usually cause mild symptoms and signs of 5yearsand8years,respectively,withthedelayrangingupto NF2.22 Nonsense/frameshift mutations produce a truncated 21 years for adults and up to 36 years for children.9 protein, and tend to be associated with a more severe phenotype, earlier onset, more rapid disease progression and higher tumor burden with more spinal and intracranial tumors in addi- Genetics tion to vestibular schwannomas.7,23 Mutations in the 3’ half of The NF2 gene is located on chromosome band 22q12, and the NF2 gene are associated with lower risk of meningioma encodes a protein known as merlin (a moesin-ezrin-radixin- than mutations in the 5’ half of the gene with a cumulative risk like protein) or schwannomin.10,11 Merlin is important in of cranial meningioma to age 50 years highest at 81% for exons 24 anchorage of the cytoskeleton to the cell membrane, the orga- 4-6, and lowest at 28% for exons 14-15. Clinical heteroge- nization of cell membrane proteins and interaction with cyto- neity amongst established NF2 families is now recognized (ie, solic proteins. The pathways involved are required for cell those in whom mosaicism is unlikely), suggesting that NF2 growth, protein translation and cellular proliferation. The gene expression may be affected by other environmental or 25 absence of normal merlin is associated with a predisposition epigenetic factors. to tumor formation.12 A detailed description of the complex In some cases, NF2 can occur in children with additional cellular and molecular neurobiology of merlin is outside the features including dysmorphism,intellectualdisabilityand scope of this article, but has been reviewed by others.8,13 congenital abnormalities, as a result of a large cytogenetically In most NF2 tumors, biallelic inactivating mutations are visible deletion including the NF2 and other genes, which may 26 found. The gene may be inactivated by mutation, silencing or be identified on karyotype or chromosomal microarray. allelic loss.14,15 NF2 has almost complete penetrance by the age of 60.1 About 50% of patients are the first affected in their family, and are NF2-Associated Tumors described as having de novo mutations. The other 50% are due Tumors occur in intracranial and spinal regions as well as on to sporadic mutations,1 which may occur in parental germline peripheral nerves, causing variable symptoms and signs depend- cells (prezygotic), or in postzygotic cells in which case ing on their location. Within the intracranial compartment, tumors Ardern-Holmes et al 11

Figure 1. NF2-associated tumors: cervical spinal ependymoma with associated syrinx in a 14-year-old shown on sagittal T2-weighted MRI (a) and postresection (d); bilateral vestibular schwannomas at age 14 years (b, e), and at 18 years (c, f) shown in T1-weighted MRI with gadolinium contrast (b, c) and T2-weighted images (e, f), larger on left (white arrows). Parasagittal meningioma also shown (f, black arrow). Abbreviations: MRI, magnetic resonance imaging; NF2, neurofibromatosis type 2. can cause deafness, blindness, headaches, seizures, gait abnorm- equivalent to 725 per 105 population compared with 1.13 per alities, and a range of other focal deficits. Spinal cord tumors 105 in the general population. Radiation associated malignant occur in between 60 to 90% of patients,23,27,28 causing sensory transformation was estimated to occur in 4717 per 105 in the and motor dysfunction including paralysis and bladder and bowel NF2 population.30 Some authors have estimated exposure to dysfunction. Pain may be a feature of central or peripheral tumors, radiotherapy increases the risk 10-fold.30,31 and is positively associated with tumor burden.29 Spinal tumors occur both within the cord (intramedullary) and within the canal on exiting nerve roots or originating from the Schwannomas meningeal covering of the cord (extramedullary). There appears Bilateral vestibular schwannomas are the characteristic tumor to be no predilection for a particular location, multiple tumors of NF2, affecting 95% of all patients, causing tinnitus, vertigo, being common in cervical, thoracic and lumbar regions. One hearing loss, and brain stem compression (Figures 1b, 1c, study examining spinal tumors found that of the 63% of NF2 1e,1f). They tend to form on the superior vestibular branch of patients affected (N 31/49), 53% had intramedullary, 55% had the eighth cranial nerve. In the general population with vestib- extramedullary tumors,¼ and 45% had at least 1 of each tumor ular schwannomas, 7% of individuals have NF2.32 Increased type.23 Multiple tumors commonly occur in a single patient. morbidity is associated with these tumors among individuals The risk of malignant transformation of tumors in individ- with NF2 compared to patients with sporadic tumors (isolated uals with NF2 is higher than in the general population. Among vestibular schwannomas associated with mutation in the NF2 1348 patients across North American and European centers, 9 gene in tumor tissue only), in part due to an increased growth cases of malignant nervous system tumors were identified, rate of tumors in NF2.33 There is significant risk that an NF2 12 Journal of Child Neurology 32(1) patient with a unilateral vestibular schwannomas will develop 2 patients experienced sensory deficits and limb ataxia. Based bilateral vestibular schwannomas, with a mean delay of 6.5 on detailed pathology studies, the authors concluded that years reported in one study. In the pediatric age group, the NF2-associated gliomas in the spinal region are almost exclu- time to development of the second vestibular schwannoma is sively ependymomas.44 These tumors can be surgically shorter; mean delay of 3.25 years for radiological evidence of resected without significant residual deficits. They are of low vestibular schwannomas and 7.3 years for hearing loss malignant potential. becoming bilateral.34 Schwannomas occur on other cranial nerves, the most common being unilateral or bilateral involvement of the trigeminal Manifestations of NF2 Affecting the Skin, nerve,28 also around the spinal cord and exiting spinal nerve roots, along peripheral nerves, and in the skin. In one series, Eyes, and Peripheral Nerves spinal and intracranial schwannomas occurred nearly as fre- Cutaneous Findings quently as vestibular schwannomas.3 Cafe´aulaitmaculesaremoreprevalentthaninthegeneral population and are often present in children with NF2 Meningiomas (Figure 2a), but rarely reach the size or numbers seen in neurofibromatosis type 1 (NF1) patients.5,45,46 They tend to Meningiomas are the second most common tumor type in NF2 be paler and have more irregular margins compared to (Figure 1f), occurring throughout the central nervous system in those of NF1.21 Hypopigmented areas can also occur.46 50-75% of individuals, often with multiple tumors.2,7,35,36 Cafe´aulaitmaculesareoftenpresentearlyinchildhood, While some meningiomas remain static and require no active followed by increase in number and size of skin tumors treatment, NF2-associated meningiomas tend to be higher over time.47 grade than sporadic tumors.37 Some meningiomas have been While about 68% of individuals have characteristic cuta- found to grow more rapidly than schwannomas, although neous features of NF2, these constitute the first recognizable growth rates are variable for both tumor types.19 Female sex symptoms or signs in up to 25% of cases.46 and younger age at NF2 diagnosis have been associated with Three types of skin tumors occur in NF2: NF2 plaques, increased growth rate in one recent report.38 nodular schwannomas,andneurofibromas (Figures 2d, 2f). While there is no specific site in which they form as com- Flat dermal NF2 plaques are cutaneous schwannomas appear- monly as vestibular schwannomas, meningiomas usually occur ing as well defined, slightly raised hyperpigmented lesions, around the spinal cord, supratentorially in the falx, and around often with excess hair, typically less than 2 cm in diameter.46 the frontal, temporal and parietal regions, including the optic During childhood, these can occur on the trunk48 as commonly nerve sheath.19 Optic nerve sheath meningiomas may be bilat- seen in adults, or on the upper and lower limbs, including hands eral, occur early in life and can be associated with complete and feet.21 Nodular schwannomas are well defined and usually vision loss.5,39,40 spherical, occurring subcutaneously around peripheral nerves. Schwannomas and meningiomas occur infrequently during There is no pigment change to the overlying skin which can be childhood, having an estimated association with NF2 in at least palpated as separate from the tumor.5 Neurofibromas, although 10-18% of cases. Constitutional NF2 is now acknowledged as classically associated with NF1, can occur in NF2, but do not the most frequent cause of meningioma presenting in child- comprise the main tumor burden.19,42 hood.41 NF2 has been diagnosed in 28% of children with optic A high burden of skin tumors is associated with increased nerve sheath meningioma.39,40 severity of disease overall, with about 10% of individuals having greater than 10 tumors.5,46 Gliomas Glial cell tumors (ependymomas and astrocytomas) are often detected radiographically, but cause symptoms less frequently Ophthalmologic Findings than other tumor types. They tend to affect the lower brain stem Ophthalmologic abnormalities are present in the majority of and upper cervical cord more often than other locations.5 The NF2 patients, including cataracts (70-80%), retinal changes prevalence of intracranial astrocytomas and ependymomas in (20-44%), strabismus (12-50%), amblyopia (12%), optic nerve NF2 varies between 1.6-4.1% and 2.5-6% respectively;42 the sheath meningiomas and other optic pathway tumors (10-27%), frequency of both tumor types is much higher (24%) in the and extra-ocular movement abnormalities (10%).9,49-51 Optic pediatric NF2 population.21 About 30% of NF2-associated nerve sheath meningiomas are the characteristic tumor of NF2, spinal tumors are intramedullary,43 and are most likely to be whereas optic pathway gliomas including the optic nerves and ependymomas (Figures 1a, 1d). These tumors occur in child- posterior optic pathway are more typical of NF1 (Figure 3).52 hood but may be clinically silent for many years. A series of Nystagmus may occur due to peripheral vestibular dysfunction 12 patients, aged between 10 to 56 years, with spinal ependy- or eye involvement. Corneal injury affects about 10% of NF2 momas was reported recently.44 Ten of 12 patients presented patients with other ocular abnormalities, and in association with gait abnormality, 8 with paresis/paralysis, 4 with pain, and with facial nerve weakness. Ardern-Holmes et al 13

Figure 2. Cutaneous and ophthalmologic findings of NF1 (a, b) and NF2 (c-f): Cafe´ au lait macules (a), pigmented cutaneous neurofibroma in NF1 with numerous other subtle raised neurofibromas on the trunk of a 15-year-old with NF1 (b). Posterior subcapsular cataract (c), optic atrophy in child with optic nerve sheath meningioma and epiretinal membrane (black arrow, e), NF2 plaque (d), and nodular schwannoma (f). Abbreviations: NF1, neurofibromatosis type 1; NF2, neurofibromatosis type 2.

Most ocular changes are congenital in origin and specific to sheath meningiomas) as retinoblastoma has resulted in enu- NF2, and as such have been highlighted as early diagnostic cleation of the globe in a number of cases. clues to NF2 in children.53 Cataracts are often bilateral, occur- A recent study of 30 patients (60% children with onset NF2 ring as posterior subcapsular or peripheral cortical lens opaci- symptoms 18 years, 40% adults onset >18 years) in a univer- ties (Figure 2c). These may not require removal, but reduce sity ophthalmology department, documented more frequent visual acuity in 10-20% of cases.9,21,49 Retinal abnormalities ophthalmologic abnormalities in the pediatric population include combined pigment epithelial and retinal hamartomas. (94%)comparedwiththeadultpopulation(67%).9 While Epiretinal membranes (Figure 2e) are recognized in association impairment in visual acuity has previously been estimated to with a severe phenotype of ocular involvement, which can lead affect over 30% of NF2 patients overall,50 this study documen- to macular impairment and retinal detachment.2,49,54 The char- ted significantly poorer visual outcomes for children, with only acteristic appearance of epiretinal membranes on ocular coher- 14% having normal visual acuity at the end of similar periods ence tomography has been described recently.50,54 of follow-up compared to 78% of adults, due to increased inci- Unfortunately, misdiagnosis of ophthalmologic complications dence of cataracts, epiretinal membranes, and optic nerve of NF2 in early childhood (retinal hamartomas and optic nerve sheath meningiomas among children.9 The authors reported a 14 Journal of Child Neurology 32(1)

Investigations Audiology Hearing evaluation typically includes pure tone audiometry, speech intelligibility assessment and brainstem auditory evoked responses for clinical evaluation, with recommendations recently published regarding optimal outcomes for use in clinical trials.58

Neuroimaging The best radiologic investigation of intracranial and spinal tumors is magnetic resonance imaging (MRI) with gadolinium contrast, including detailed views of the internal auditory canal (a minimum of 3 mm slices in both axial and coronal planes for clinical evaluation).19,21 Volumetric approaches to tumor measurement provide the most sensitive assessment of tumor size for vestibular schwannomas both for monitoring disease progression and response to treatment.59-61 Whole body MRI to assess total tumor burden may play an increasing role in management of patients with NF2.62 Awholebodyapproach allows identification of symptomatic or potentially symptomatic lesions. Radiologic response to systemic therapy may ideally include multiple target tumors in future reflecting the complexity and multiplicity of tumors and clinical symptoms in NF2. However, the role of whole body MRI is not clearly Figure 3. Optic nerve sheath meningioma in a 7-year-old with NF2 established as yet. (left side a, c) and optic nerve glioma in a 10-year-old with NF1 (right side b, d) shown on axial T1-weighted MRI (a noncontrast, b with contrast) and coronal T1-weighted images (c, d both with contrast). Other Investigations Abbreviations: MRI, magnetic resonance imaging; NF1, neurofibro- Fluoro-deoxy glucose positron emission tomography may have matosis type 1; NF2, neurofibromatosis type 2. a role in selected cases where malignant transformation is suspected. Depending on the clinical context, a range of other significant correlation between younger age of onset and investigations may be needed to evaluate new symptoms or increased number of central nervous system tumors. deficits, including nerve conduction studies, electroencephalography, and other functional studies. Peripheral Neuropathy Peripheral nerve dysfunction can occur in NF2 without obvious focal tumor. Cranial nerve deficits are more frequent present- Clinical Course ing signs in childhood than adulthood, occurring in 40% of While individuals with NF2 typically experience progressive children in one study (eg, commonly facial palsy, strabismus symptoms and signs of disease, the clinical course varies due to third nerve palsy, swallowing impairment, tongue atro- between individuals, depending on age of onset, genotype, phy).4 Children may also present with a mononeuropathy in the tumor burden, complications and management. Saltatory limbs, most commonly foot drop, in the absence of a focal brain growth (alternating periods of growth and quiescence) is most stem, spinal cord or peripheral nerve tumor.5,55 Marked wast- common for NF2-associated tumors, although linear growth ing may be associated with the foot drop, and significant wast- and exponential growth do occur.38 Age of onset and age of ing can also be seen in the hands, most prominently in the diagnosis are the 2 most important factors in predicting disease thenar and hypothenar eminences.17 severity.22,25 The presence of meningiomas and treatment in The peripheral neuropathy associated with NF2 tends to be a nonspecialist centers have also been associated with risk of mixed motor and sensory axonal neuropathy occurring in a earlier mortality.22 glove and stocking distribution, with distal weakness, fascicu- Natural history studies of vestibular schwannomas, have lations and hypaesthesia.5,56,57 Pathologic studies have identi- demonstrated progressive disease over time, though rate of fied loss of both myelinated and unmyelinated nerve fibers, progression varies between tumors, and change in hearing is sometimes with an onion bulb appearance.56 Schwann cell and not necessarily directly correlated with tumor growth.63,64 Sig- epineurial cell proliferation with entanglement of axons has nificant tumor progression (defined as 20% increase in tumor been described, without formation of a discrete tumor.56,57 volume) of 31% at 1 year and 79% at 3 years has been reported Ardern-Holmes et al 15 in 120 patients (200 tumors), associated with cumulative hear- procedures and one received radiation therapy for progressive ing decline of 16% over 3 years (defined as decrease in word orbital meningioma. Outcomes were assessed across 4 recognition score exceeding the 95% critical difference com- domains—hearing, vision, ambulation, and school perfor- pared with baseline).65 mance. By 18 years of age, 83% of patients had visual impair- The natural history of 287 cranial meningiomas in 74 ment, 75% had hearing loss (bilateral in 2 patients). One patient patients with NF2 was reported recently, with a mean follow- was paraparetic, 2 others had difficulties with ambulation. In up of 9 years. About one-quarter of the group were aged all, 25% were functioning below age expectation at school, <18 years at the time of diagnosis. In this group of patients, attributable to physical impairments and frequent hospitaliza- 69% had at least a single operation for vestibular schwanno- tion rather than baseline intellectual disability. Two children mas, 23% for spinal tumors.36 Significant growth of at least 1 had impairments in all 4 domains. The authors highlighted meningioma during 1 year ( 20% increase in volume) was significant morbidity despite active surveillance in familial found in 28% of patients (7.3% of 267 tumors). 46% required cases and early surgical intervention.4 surgical treatment for meningioma, for variable indications In 2005, Ruggieri et al21 described 24 individuals aged including epilepsy, intracranial hypertension and specific neu- between 4 to 22 years followed at a European center. Nineteen rologic deficits.36 were 10 years old at the time of diagnosis, 22 were diagnosed Limited data are available regarding longevity in NF2. aged 18 years. Bilateral vestibular schwannomas were pres- However, 38% survival at 20 years from diagnosis, has been ent in 75% patients, with unilateral vestibular tumors in 16%. estimated for the population as a whole.66 Other intracranial tumors included meningiomas (66% patients), astrocytomas (25%), ependymomas (25%), and other Clinical Presentation and Natural History cranial nerve tumors (40%). Brainstem tumors were associated with a poor prognosis. Twenty-one individuals had spinal of Pediatric Cases tumors with successful resection achieved in 4 of 21 children Presentation of NF2 in the pediatric age group is often unrec- with extradural lesions, and 3 with intradural tumors. Surgical ognized. In a group of 368 individuals reported previously, 153 treatment had been provided for 16 of 24 patients. 50% suffered (42%)hadonsetofsymptomsbetween1-19yearsofage.22 significant morbidity during childhood, including 2 children While adults typically present with hearing loss and tinnitus who did not survive beyond 16 years of age.21 as a consequence of vestibular schwannomas, these symptoms Other case reports have documented early mortality asso- often follow other presenting features in the pediatric popula- ciated with NF2, including a patient presenting at age tion. In fact, vestibular schwannomas account for only15-30% 13 years with multiple craniospinal tumors, who died 4 years of presenting symptoms in pediatric cases.55 Symptoms of ves- later despite multimodal treatment including surgery and tibular schwannoma have been delayed by over 40 years in chemotherapy.69 some patients presenting in childhood.67 Children are more likely to present with visual symptoms, spinal cord compression or neurologic symptoms from other intracranial Management 2,4,45,68 tumors. Furthermore, where both vestibular schwanno- Patients are best managed in tertiary centers by a well- mas and spinal tumors are present, children are more likely to resourced multidisciplinary specialist team experienced in be symptomatic from spinal tumors than from vestibular dealing with the multiple complications associated with 3 schwannomas. Astute clinicians may suspect the diagnosis NF2.22 Specialties involved may include neurology, genetics, of NF2 based on cutaneous or ophthalmologic manifestations ophthalmology, audiology, dermatology, radiology, neurosur- alone in a proportion of children. gery, otolaryngology, medical and radiation oncology, clinical In five pediatric case series (total N 109), mean age at first nurse consultants, allied health staff, and psychologists. presentation varied between 5.5-7.0 years,¼ while mean age at diagnosis varied from 8.8 to 14.9 years.2,4,21,55,68 The presenting features of these children are summarized in Table 2. Follow-Up of Children With Suspected NF2 Tumor burden and associated morbidity and mortality Children with suspected NF2 require ongoing follow-up to among children are typically higher than in the adult NF2 clarify the diagnosis over time; this may be based on the devel- population. Among 12 children from a North American tertiary opment of additional clinical features, and/or on genetic testing NF treatment center,4 hearing loss associated with vestibular to identify NF2 mutations in blood and tumor (Table 3). schwannomas was present by age 18 years in 75% of patients. Molecular genetic testing is recommended for children of Seven children underwent surgical treatment for vestibular affected parents, recognizing that clinical features may be schwannomas at an average age of 10 years, with immediate insufficient to meet diagnostic criteria for NF2 until later in postoperative hearing loss in 4 cases. Progressive hearing loss life. Leukocyte DNA from blood is usually tested in children occurred in all patients over time. All children had other intra- of parents with NF2 (Table 3). Alongside genetic testing, cranial tumors, including 83% schwannomas, and 75% menin- baseline skin, neurology and ophthalmology (including slit- giomas; 75% also had spinal tumors. Only 2 patients were not lamp) assessments are required, with annual clinical reviews treated surgically during childhood. One child had undergone 5 thereafter. Hearing assessment and craniospinal MRI should 16

Table 2. Presenting Symptoms of NF2 Populations and Among Pediatric Patients.

Muscle Hearing Vertigo/loss weakness/ Facial Visual Sensory Foot Age group loss Tinnitus of balance wasting nerve palsy Seizures Pain Headache involvement symptoms drop Cutaneous Other References

All ages (2-52 44 10 8 12 — 8 4 — 1 2- — NI 11 Evans et al5 years) presymptomatic N 100 ¼ All ages (7-71 19 7 2 3 —23 2 10 —— 8b 2(3.4%)c Parry et al45 years) (30%) (11%) (3.4%) (4%) (3.4%) (4%) (3.4%) (16.4%)a (13%) 5(8%) N 63 Presymptomatic ¼ 10 years 2 —— — 3 3 —1 1 —1NI — Evans et al5 N 11 (18%) (27%) (27%) (9%) (9%) (9%) ¼

<16 years 1 —— 2 —12 —8d 5e —MacCollinand N 18 (5%) (9%) (5%) (9%) (44%) (28%) Mautner2 ¼ Mautner et al48 10 years 4 1— 3f 5g 8 —2 4h 1 1 1 1 Evans et al55 N 30 (13.5%) (10%) (17%) (27%) (6%) (13.5%) (3%) (3%) (3%) (3%) ¼ Weight loss (glioma) 17 years 3 1 —22 —— — 1 ——NI3i Nunes and N 12 (25%) (8.3%) (16.5%) (16.5%) (8.3%) (25%) MacCollin4 ¼ 15 years 1 2 —61 1 1 —7j ——8CAL 3k Ruggieri et al21 N 24 (4%) (8%) (25%) (4%) (4%) (4%) (29%) (33%) (12.5%) ¼ 3 tumors (12.5%) <17 years 5 — — — — See See —3—See5b ( 1 5l 6m Choi et al68 N 25 (20%) other other (12%) other CAL)þ (20%þ 24%) ¼ (24%) þ

Abbreviations: CAL, cafe´ au lait; NF2, neurofibromatosis type 2; NI, not included: skin lumps and cataracts excluded in Evans et al5 as usually asymptomatic, skin lumps and amblyopia (nonspecific) not included.4 aOcular cause of vision loss (n 7), central nervous system tumor (n 2), diplopia (n 1). bPainful or growing skin tumors. cPersonality change and dysphagia. dCataracts (n 3), oculomotor nerve (n 2), diplopia, epiretinal hamartoma, epiretinal¼ membrane (n 1). eOculomotor nerve¼ and skin (n 1).¼fSpinal schwannomas (n 2), neuropathy (n 1). gPresumed secondary to vestibular schwannoma.¼ hPlus nystagmus¼ due to retinal hamartoma (n 1). iSwallowing difficulty, foot¼ eversion, nystagmus. jStrabismus (n ¼3), amblyopia and strabismus¼ (n 2), cataract (n¼ 1), amblyopia (n 1), pigmentary retinal hyperplasia (n 1). kPtosis (n 2), voice changes/hiccups¼ (n 1). lGait disturbance, leg or neck pain, foot drop due to peripheral¼ nerve sheath or intradural-extramedullary¼ tumor.¼ mSeizure, abdominal¼ pain, incidental finding on chest¼ X-ray, hoarseness¼ (n 2). ¼ ¼ Ardern-Holmes et al 17

Table 3. Recommended Follow-Up for Children at Risk of Having NF2.

Child with suspected NF2 (schwannoma, meningioma, Child of affected parents (50% risk) skin featuresa)

Baseline Birth—ocular, skin, neurological formal ophthalmology exam Ocular, skin, neurological exam assessment during early years þ Audiology Full craniospinal MRI DNA analysis Presymptomatic diagnosis if familial mutation known Mutation analysis (blood and tumor) Mutation found in blood: No mutation in blood: NF2 not excluded follow-up NF2 carrier follow-up No mutation in blood, 2 mutations in tumor:! Mutation not! found in blood: NF2 excludedb infrequent follow-up NF2 excluded no follow-up ! Follow-up 2-10 years of age:! 2-10 years: clinical Annual ocular, skin, neurological Annual ocular, skin, neurological neuroimaging Formal ophthalmology assessment if symptomatic Ophthalmology, audiology 10-30 years of age: >10 years of age: As above audiology As above neuroimaging if not already indicated on >10 yearsþ of age: clinical groundsþ Baseline craniospinal MRI or <10 years of age: At any stage based on clinical suspicion As clinically indicated Tumor follow-up as suspected NF2 >10 years: No tumor! cranial MRI every 2 years to age 20 years, then Repeat craniospinal MRI every 3 years! Then annual cranial MRI Spinal tumors present annual spinal MRI ! Source: Modified from Ruggieri et al21 and Janse et al.70 Abbreviations: MRI, magnetic resonance imaging; NF2, neurofibromatosis type 2. aFewer than 6 CAL (cafe-au-lait macules) macules, ie, not fulfilling criteria for neurofibromatosis type 1 or skin lumps. bOther than small risk of mosaicism. occur from 10 years of age, unless clinical suspicion mandates Table 4. Recommended Follow-Up for Confirmed Cases of NF2. earlier assessment.52 Frequency In suspected sporadic cases, genetic testing is first performed on tumor DNA, with a view to identifying NF2 muta- Clinical examination tions on both alleles. This is followed by testing of leukocyte Neurologic examination Annual DNA to establish which mutation is constitutional and which is Skin examination Annual somatic (present only in the tumor). Failure to detect a mutation Ophthalmologic examination Annual Audiologic examination 6-12 monthsa in blood may occur due to mosaicism, mutations located in Pure tone audiometry intronic or promotor regions, or due to large multiexonic dele- Speech recognition 4 tions. This can occur in patients presenting with unilateral BAER vestibular schwannoma. Additional features of NF2 may be Neuroimaging—contrast enhanced MRI identifiable over time in a proportion of patients. Therefore, Brain with IACs 6-12 monthsa a careful multimodal follow-up is indicated (outlined in Table 3) Spine 6-12 months to identify and treat complications early. Annual MRI scans are Psychosocial support 7,52 Assess employment/school/family Annual recommended from the age of 10 years. Only when muta- functioning tion in blood is negative, and 2 NF2 mutations are identified in Genetic counseling At diagnosis then at any stage tumor, is the diagnosis of constitutional NF2 unlikely.70 Source: Modified from MacCollin and Mautner,2 Evans,7 Asthagiri et al,8 Ardern-Holmes and North,52 and Janse et al.70 Surveillance and Secondary Prevention in Confirmed NF2 Abbreviations: BAER, brainstem auditory evoked response; IAC, internal auditory canal; MRI, magnetic resonance imaging; NF2, neurofibromatosis type 2. Most individuals diagnosed with NF2 should be followed with aFrequency of follow-up is dependent on age and disease burden. aminimumofannualclinicalevaluationandinvestigations, with increased frequency in the presence of significant compli- in recent years, with a major focus on symptomatic, progressive 66,75 cations (Table 4). Some adults with mild disease presenting in vestibular schwannomas. The most effective agent to date later life, may be managed with less frequent assessments. inhibits vascular endothelial derived growth factor, which has a central role in angiogenesis for NF2 schwannomas.71 Anti– vascular endothelial derived growth factor monoclonal antibo- Medical Management dies such as bevacizumab (administered as a fortnightly intra- Significant effort has been invested in developing medical venous infusion) provide a beneficial effect in treatment of treatments for NF271-74 and appropriate clinical trial protocols vestibular schwannomas including tumor shrinkage and 18 Journal of Child Neurology 32(1) hearing improvement in a proportion of patients.76,77 The larg- Complete resection of schwannomas for NF2 patients is est series reported to date included 31 patients aged between achievable at lower rates than for sporadic tumors,83 presum- 12-73 years (median 26 years) with progressive vestibular ably because the schwannomas of NF2 tend to incorporate schwannomas showing a median of 64% volume increase dur- more nerve fascicles, with increased adherence to surrounding ing 12 months prior to treatment. Tumor shrinkage ( 20% nerves.84 Risks associated with vestibular schwannoma resec- volume) was documented for 55% (17/31) patients, constitut- tion include hearing loss and damage to the facial nerve. Some ing radiographic response, while 57% (13/17) patients experi- surgeons advocate for early surgery when vestibular schwan- enced hearing improvement based on a statistically significant nomas are <2 cm in greatest diameter, to achieve hearing pre- increase in word recognition score. Both radiographic and hear- servation with minimal surgical risks.28,85 Other approaches ing improvements were sustained for up to 1 year in about 90% include decompression of the internal auditory canal without of patients, with stable to improved status in 61% and 54% for tumor removal or partial tumor debulking to relieve symptoms hearing and tumor volumes respectively after 3 years.78 Lim- of brain stem compression.28 A specific aim is to preserve the ited efficacy in slowing progression of meningiomas has also cochlear nerve, due to the potential future utility of a cochlear been documented.73,79 Although progressive vestibular implant, which can provide stable serviceable hearing over at schwannomas remain the primary indication for treatment, least 8 years in the majority of patients.86 Approaches to bevaizumab should also be considered for other progressive improving cosmesis, in the event of facial nerve damage, have symptomatic NF2-associated tumors. Symptomatic benefit was been described, along with recommendations for assessing recently reported in a series of 8 patients with spinal ependy- facial nerve outcomes in the course of treatment.58 momas, with radiologic response demonstrated in 5 cases based Rates of hearing preservation up to 50% over 3 years post- on a >20% reduction in linear measurements.80 operatively have been reported by Friedman and colleagues.85 Lapatinib (available as an oral tablet) targets the epidermal In a group of 35 children with NF2 (47 vestibular schwannoma growth factor receptor (EGFR/Erb2 inhibitor), and had some resections performed between 1992 and 2004), 55% of sur- effect on vestibular schwannomas in a single institution phase geries achieved hearing preservation at 70 dB, with a similar II study (21 patients, 4 aged <18 years).81 Radiographic hearing level to that reported in Friedman’s study (48%).87 In response ( 15% tumor volume reduction), occurred in 4 of another series of 29 pediatric patients (23/29 with NF2), hear- 17 evaluable patients (23.5%), varying from 15.7 to 23.9% ing preservation was possible in only 30% of cases, with volume reduction over a median of 4.5 months. Hearing greater risk of hearing loss and facial nerve damage (8%) fol- response (defined as 10 dB improvement in pure tone average lowing resection of larger tumors.83 or statistically significant improvement in word recognition Surgery is required in up to 30-60% of patients with spinal score) was recorded in 4 of 13 eligible patients. Median time tumors with likelihood of surgery varying by tumor location to progression was 14 months (based on either volume increase (extramedullary tumors more likely).23,28 or hearing loss), and overall progression-free survival at Because surgery carries the risk of exacerbating neurologic 12 months was estimated at 64.7%.81 deficits and other complications, evolving medical options are Other agents such as mammalian target of rapamycin favored where available. (mTOR) inhibitors may halt tumor progression.82 Medical therapies for this population must be tolerable, with care given to minimizing side effects. For young adults receiv- Radiotherapy/Radiosurgery ing bevacizumab or other agents which can affect future ferti- Stereotactic radiosurgery for vestibular schwannomas has lity, anticipatory care shouldincludeconsultationwith been estimated to achieve tumor control in between 60-80% reproductive specialists. of the general NF2 population at 5 years,88 significantly better Peripheral neuropathies that are unrelated to tumors can be than the natural history of the disease. Hearing preservation in treated symptomatically, with drugs such as gabapentin or those with serviceable hearing was estimated at 73% after one pregabalin to control pain and other sensory symptoms.8 year, 59% after 2 years and 48% after 5 years, with low risk of injury to the facial (5-12%)andtrigeminalnerves(2-7%).88,89 Long-term results are less robustthanforsporadicvestibular 66 Surgical Management schwannomas. In one pediatric case series, while hearing preservation after gamma knife surgery compared favorably Until recently, surgery has been the mainstay of treatment for with adult patients (67% at 1 year, 53% at 5 years, n 11 NF2-associated tumors, and continues to play an important role tumors), tumor control was poor (35% at 3 years, n ¼ 17 for most patients.28,66 Surgical management should be care- tumors).68 It should be noted that these studies have utilized¼ fully planned by surgeons experienced in the care of NF2 alternative defined endpoints versus those recently recom- patients. The aim is to remove tumors before they cause irre- mended for studies of NF2 patients.59 Optimal comparability versible damage, minimizing potential adverse surgical conse- between natural history and treatment outcome datasets is quences, bearing in mind that operative morbidity increases dependent on measurement standardization. with size of the tumor.8,28 Tumor should be reserved for genetic There is concern regarding the increased risk of malignant testing, with patient consent.42 transformation after radiosurgery in NF2.30,31 While NF2 Ardern-Holmes et al 19 patients number about 7% in studies of vestibular schwanno- Author Contributions mas treated with gamma knife surgery, nearly half of the cases SAH contributed to writing and editing the manuscript. GF contrib- of malignant change occur in the NF2 population, indicating 31 uted to writing the manuscript. KN reviewed and edited the final that this treatment modality should be utilized with caution. version. All authors approved the final version. Nevertheless, radiosurgery and radiotherapy may have a role in management of selected vestibular and other tumors, such as Declaration of Conflicting Interests optic nerve sheath meningiomas.40,89,90 The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Assistive Devices and Psychosocial Management Optimizing quality of life through enhanced community par- Funding ticipation can be achieved using a range of approaches includ- The authors disclosed receipt of the following financial support for the ing assistive devices to improve vision and communication research, authorship, and/or publication of this article: This work was (auditory brainstem implants, cochlear implants,83 and lip read- supported by funding from the Children’s Tumour Foundation, ing). Allied health support to maximize ambulatory function Australia. and minimize risk of injury is important. Psychosocial support for affected individuals and families is critical. References 1. Evans DG, Huson SM, Donnai D, et al. A genetic study of type 2 Clinical Trials for NF2 neurofibromatosis in the United Kingdom. I. Prevalence, mutation rate, fitness, and confirmation of maternal transmission effect Information regarding clinical trials for NF2 patients can be on severity. JMedGenet.1992;29:841-846. found at www.uab.edu/nfconsortium/clinical-trials (Neurofi- 2. MacCollin M, Mautner VF. The diagnosis and management of bromatosis Clinical Trials Consortium) and www.clinicaltrials. neurofibromatosis 2 in childhood. Semin Pediatr Neurol.1998;5: gov (US National Institutes of Health). 243-252. 3. Mautner VF, Lindenau M, Baser ME, et al. The neuroimaging and clinical spectrum of neurofibromatosis 2. Neurosurgery.1996;38: Conclusion 880-885; discussion 885-886. NF2 is a rare autosomal dominant neurocutaneous disorder 4. Nunes F, MacCollin M. Neurofibromatosis 2 in the pediatric pop- associated with multisystem effects, predominant in the cen- ulation. JChildNeurol.2003;18:718-724. tral nervous system, related to loss of tumor suppressor func- 5. Evans DG, Huson SM, Donnai D, et al. A clinical study of type 2 tion. Presentation in childhood isassociatedwithmoresevere neurofibromatosis. Q J Med.1992;84:603-618. disease and risk of significant early morbidity and mortality. 6. Neurofibromatosis. Conference statement. National Institutes of While diagnosis in adults can be delayed due to a limited Health Consensus Development Conference. Arch Neurol.1988; awareness of the condition among physicians, the challenge 45:575-578. of timely diagnosis in children is further complicated by the 7. Evans DG. Neurofibromatosis 2 [Bilateral acoustic neurofibroma- variable presentation in this agegroup.Furthermore,theclin- tosis, central neurofibromatosis, NF2, neurofibromatosis type II]. ical diagnostic criteria used for adults may not be met during Genet Med.2009;11:599-610. childhood. Careful skin and eye examination may uncover 8. Asthagiri AR, Parry DM, Butman JA, et al. Neurofibromatosis helpful clinical signs of NF2 in children. A high index of type 2. Lancet.2009;373:1974-1986. suspicion, genetic testing and attentive clinical follow-up are 9. Bosch MM, Boltshauser E, Harpes P, Landau K. Ophthalmologic needed to establish the diagnosis. When NF2 is confirmed, findings and long-term course in patients with neurofibromatosis comprehensive multimodal surveillance is recommended at a type 2. Am J Ophthalmol.2006;141:1068-1077. minimum of annual intervals, and more frequently in cases 10. Rouleau GA, Wertelecki W, Haines JL, et al. Genetic linkage of where progressive disease and significant complications have bilateral acoustic neurofibromatosis to a DNA marker on chromo- been identified. The involvement of experienced specialist some 22. Nature.1987;329:246-248. teams familiar with NF2 is recommended to optimize disease 11. Rouleau GA, Merel P, Lutchman M, et al. Alteration in a new specific care and outcomes, and to facilitate inclusion of gene encoding a putative membrane-organizing protein causes adults and children in natural history studies and treatment neuro-fibromatosis type 2. Nature.1993;363:515-521. trials wherever possible. 12. Lee JY, Kim H, Ryu CH, et al. Merlin, a tumor suppressor, interacts with transactivation-responsive RNA-binding protein and inhibits its oncogenic activity. JBiolChem.2004;279: Acknowledgments 30265-30273. We would like to thank patients from the Neurogenetics Clinic at the 13. Hanemann CO. Magic but treatable? Tumours due to loss of Children’s Hospital at Westmead who consented to clinical photogra- merlin. Brain.2008;131:606-615. phy. We also thank Associate Professor John Grigg, University of 14. Evans DG, Maher ER, Baser ME. Age related shift in the muta- Sydney, for providing photographs of ophthalmologic signs in NF2. tion spectra of germline and somatic NF2 mutations: 20 Journal of Child Neurology 32(1)

hypothetical role of DNA repair mechanisms. JMedGenet. radiation for benign disease: substantial risks in certain tumour 2005;42:630-632. prone syndromes. JMedGenet.2006;43:289-294. 15. Warren C, James LA, Ramsden RT, et al. Identification of recur- 32. Evans DG, Moran A, King A, Saeed S, Gurusinghe N, Ramsden rent regions of chromosome loss and gain in vestibular schwan- R. Incidence of vestibular schwannoma and neurofibromatosis 2 nomas using comparative genomic hybridisation. J Med Genet. in the North West of England over a 10-year period: higher 2003;40:802-806. incidence than previously thought. Otol Neurotol.2005;26: 16. Kluwe L, Mautner V, Heinrich B, et al. Molecular study of fre- 93-97. quency of mosaicism in neurofibromatosis 2 patients with bilat- 33. Otsuka G, Saito K, Nagatani T, Yoshida J. Age at symptom onset eral vestibular schwannomas. JMedGenet.2003;40:109-114. and long-term survival in patients with neurofibromatosis type 2. 17. Lloyd SK, Evans DG. Neurofibromatosis type 2 (NF2): diagnosis JNeurosurg.2003;99:480-483. and management. Handb Clin Neurol.2013;115:957-967. 34. Evans DG, Lye R, Neary W, et al. Probability of bilateral disease 18. Ahronowitz I, Xin W, Kiely R, Sims K, MacCollin M, Nunes FP. in people presenting with a unilateral vestibular schwannoma. J Mutational spectrum of the NF2 gene: a meta-analysis of 12 years Neurol Neurosurg Psychiatry.1999;66:764-767. of research and diagnostic laboratory findings. Hum Mutat.2007; 35. Goutagny S, Kalamarides M. Meningiomas and neurofibromato- 28:1-12. sis. JNeurooncol.2010;99:341-347. 19. Evans DG, Sainio M, Baser ME. Neurofibromatosis type 2. JMed 36. Goutagny S, Bah AB, Henin D, et al. Long-term follow-up of 287 Genet.2000;37:897-904. meningiomas in neurofibromatosis type 2 patients: clinical, radiolo- 20. Evans DG, Ramsden RT, Gokhale C, Bowers N, Huson SM, gical, and molecular features. Neuro Oncol.2012;14:1090-1096. Wallace A. Should NF2 mutation screening be undertaken in 37. Perry A, Giannini C, Raghavan R, et al. Aggressive phenotypic patients with an apparently isolated vestibular schwannoma? Clin and genotypic features in pediatric and NF2-associated meningio- Genet.2007;71:354-358. mas: a clinicopathologic study of 53 cases. JNeuropatholExp 21. Ruggieri M, Iannetti P, Polizzi A, et al. Earliest clinical manifesta- Neurol.2001;60:994-1003. tions and natural history of neurofibromatosis type 2 (NF2) in 38. Dirks MS, Butman JA, Kim HJ, et al. Long-term natural history of childhood: a study of 24 patients. Neuropediatrics.2005;36:21-34. neurofibromatosis type 2-associated intracranial tumors. JNeu- 22. Baser ME, Friedman JM, Aeschliman D, et al. Predictors of the rosurg.2012;117:109-117. risk of mortality in neurofibromatosis 2. Am J Hum Genet.2002; 39. Bosch MM, Wichmann WW, Boltshauser E, Landau K. Optic 71:715-723. nerve sheath meningiomas in patients with neurofibromatosis 23. Patronas NJ, Courcoutsakis N, Bromley CM, Katzman GL, Mac- type 2. Arch Ophthalmol.2006;124:379-385. Collin M, Parry DM. Intramedullary and spinal canal tumors in 40. Harold Lee HB, Garrity JA, Cameron JD, Strianese D, Bonavo- patients with neurofibromatosis 2: MR imaging findings and cor- lonta G, Patrinely JR. Primary optic nerve sheath meningioma in relation with genotype. Radiology.2001;218:434-442. children. Surv Ophthalmol.2008;53:543-558. 24. Smith MJ, Higgs JE, Bowers NL, et al. Cranial meningiomas in 411 41. Evans DG, Watson C, King A, Wallace AJ, Baser ME. Multiple neurofibromatosis type 2 (NF2) patients with proven gene muta- meningiomas: differential involvement of the NF2 gene in chil- tions: clear positional effect of mutations, but absence of female dren and adults. JMedGenet.2005;42:45-48. severity effect on age at onset. JMedGenet.2011;48:261-265. 42. Evans DG. Neurofibromatosis type 2 (NF2): a clinical and mole- 25. Selvanathan SK, Shenton A, Ferner R, et al. Further genotype– cular review. Orphanet J Rare Dis.2009;4:16. phenotype correlations in neurofibromatosis 2. Clin Genet.2010; 43. Mautner VF, Tatagiba M, Lindenau M, et al. Spinal tumors in 77:163-170. patients with neurofibromatosis type 2: MR imaging study of 26. Barbi G, Rossier E, Vossbeck S, et al. Constitutional de novo frequency, multiplicity, and variety. AJR Am J Roentgenol. interstitial deletion of 8 Mb on chromosome 22q12.1-12.3 encom- 1995;165:951-955. passing the neurofibromatosis type 2 (NF2) locus in a dysmorphic 44. Hagel C, Stemmer-Rachamimov AO, Bornemann A, et al. girl with severe malformations. JMedGenet.2002;39:E6. Clinical presentation, immunohistochemistry and electron 27. Mautner VF. Spinal tumors in patients with neurofibromatosis microscopy indicate neurofibromatosis type 2-associated glio- type 2: MR imaging study of frequency, multiplicity and variety. mas to be spinal ependymomas. Neuropathology.2012;32: AJR Am J Roentgenol.1996;166:1231. 611-616. 28. Hoa M, Slattery WH III. Neurofibromatosis 2. Otolaryngol Clin 45. Parry DM, Eldridge R, Kaiser-Kupfer MI, Bouzas EA, Pikus A, North Am.2012;45:315-332;viii. Patronas N. Neurofibromatosis 2 (NF2): clinical characteristics of 29. Merker VL, Bredella MA, Cai W, et al. Relationship between 63 affected individuals and clinical evidence for heterogeneity. whole-body tumor burden, clinical phenotype, and quality of life Am J Med Genet.1994;52:450-461. in patients with neurofibromatosis. Am J Med Genet A.2014; 46. Mautner VF, Lindenau M, Baser ME, Kluwe L, Gottschalk J. Skin 164A:1431-1437. abnormalities in neurofibromatosis 2. Arch Dermatol.1997;133: 30. Baser ME, Evans DG, Jackler RK, Sujansky E, Rubenstein A. 1539-1543. Neurofibromatosis 2, radiosurgery and malignant nervous system 47. Cruz MJ, Baudrier T, Gil-Da-Costa MJ, Azevedo F, Mota A. tumours. Br J Cancer.2000;82:998. Multiple cutaneous plexiform schwannomas revealing neurofi- 31. Evans DG, Birch JM, Ramsden RT, Sharif S, Baser ME. Malig- bromatosis type 2 in a child—report of a novel mutation in this nant transformation and new primary tumours after therapeutic rare association. Eur J Dermatol.2011;21:1010-1011. Ardern-Holmes et al 21

48. Mautner VF, Tatagiba M, Guthoff R, Samii M, Pulst SM. Neu- 65. Plotkin SR, Merker VL, Muzikansky A, Barker FG II, Slattery W rofibromatosis 2 in the pediatric age group. Neurosurgery.1993; III. Natural history of vestibular schwannoma growth and hearing 33:92-96. decline in newly diagnosed neurofibromatosis type 2 patients. 49. Ragge NK, Baser ME, Riccardi VM, Falk RE. The ocular presen- Otol Neurotol.2014;35:e50-e56. tation of neurofibromatosis 2. Eye (Lond).1997;11(pt1):12-18. 66. Blakeley JO, Evans DG, Adler J, et al. Consensus recommendations 50. Bouzas EA, Parry DM, Eldridge R, Kaiser-Kupfer MI. Visual for current treatments and accelerating clinical trials for patients with impairment in patients with neurofibromatosis 2. Neurology. neurofibromatosis type 2. Am J Med Genet A.2012;158A:24-41. 1993;43:622-623. 67. Evans DG: Neurofibromatosis type 2: genetic and clinical fea- 51. Feucht M, Griffiths B, Niemuller I, Haase W, Richard G, Mautner tures. Ear Nose Throat J.1999;78:97-100. VF. Neurofibromatosis 2 leads to higher incidence of strabismo- 68. Choi JW, Lee JY, Phi JH, et al. Clinical course of vestibular logical and neuro-ophthalmological disorders. Acta Ophthalmol. schwannoma in pediatric neurofibromatosis type 2. JNeurosurg 2008;86:882-886. Pediatr.2014;13:650-657. 52. Ardern-Holmes SL, North KN. Therapeutics for childhood neu- 69. Stachowicz-Stencel T, Synakiewicz A, Bien E, Adamkiewicz- rofibromatosis type 1 and type 2. Curr Treat Options Neurol. Drozynska E, Wybieralska-Dubaniewicz M, Balcerska A. Multi- 2011;13:529-543. ple primary cranio-spinal tumours in a 13-year-old female with 53. Kaye LD, Rothner AD, Beauchamp GR, Meyers SM, Estes ML. neurofibromatosis type 2 management strategy. Childs Nerv Syst. Ocular findings associated with neurofibromatosis type II. 2011;27:175-178. Ophthalmology.1992;99:1424-1429. 70. Janse AJ, Tan WF, Majoie CB, Bijlsma EK. Neurofibromatosis 54. Sisk RA, Berrocal AM, Schefler AC, Dubovy SR, Bauer MS. type 2 diagnosed in the absence of vestibular schwannomas. A Epiretinal membranes indicate a severe phenotype of neurofibro- case report and guidelines for a screening protocol for children at matosis type 2. Retina.2010;30:S51-58. risk. Eur J Pediatr.2001;160:439-443. 55. Evans DG, Birch JM, Ramsden RT. Paediatric presentation of 71. Widemann BC, Acosta MT, Ammoun S, et al. CTF meeting 2012: type 2 neurofibromatosis. Arch Dis Child.1999;81:496-499. translation of the basic understanding of the biology and genetics 56. Sperfeld AD, Hein C, Schroder JM, Ludolph AC, Hanemann CO. of NF1, NF2, and schwannomatosis toward the development of Occurrence and characterization of peripheral nerve involvement effective therapies. Am J Med Genet A.2014;164A:563-578. in neurofibromatosis type 2. Brain.2002;125:996-1004. 72. Kissil JL, Blakeley JO, Ferner RE, et al. What’s new in neurofi- 57. Hagel C, Lindenau M, Lamszus K, Kluwe L, Stavrou D, bromatosis? Proceedings from the 2009 NF Conference: new Mautner VF. Polyneuropathy in neurofibromatosis 2: clinical frontiers. Am J Med Genet A.2010;152A:269-283. findings, molecular genetics and neuropathological alterations 73. Kalamarides M, Acosta MT, Babovic-Vuksanovic D, et al. Neu- in sural nerve biopsy specimens. Acta Neuropathol.2002;104: rofibromatosis 2011: a report of the Children’s Tumor Foundation 179-187. annual meeting. Acta Neuropathol.2012;123:369-380. 58. Plotkin SR, Ardern-Holmes SL, Barker FG II, et al. Collaboration 74. Plotkin SR, Albers AC, Babovic-Vuksanovic D, et al. Update REI: hearing and facial function outcomes for neurofibromatosis from the 2013 International Neurofibromatosis Conference. Am 2clinicaltrials.Neurology.2013;81:S25-S32. JMedGenetA.2014;164A:2969-2978. 59. Plotkin SR, Halpin C, Blakeley JO, et al. Suggested response cri- 75. Evans DG, Kalamarides M, Hunter-Schaedle K, et al. Consensus teria for phase II antitumor drug studies for neurofibromatosis type recommendations to accelerate clinical trials for neurofibromato- 2relatedvestibularschwannoma.JNeurooncol.2009;93:61-77. sis type 2. Clin Cancer Res.2009;15:5032-5039. 60. Harris GJ, Plotkin SR, Maccollin M, et al. Three-dimensional 76. Plotkin SR, Stemmer-Rachamimov AO, Barker FG II, et al. Hear- volumetrics for tracking vestibular schwannoma growth in neu- ing improvement after bevacizumab in patients with neurofibro- rofibromatosis type II. Neurosurgery.2008;62:1314-1319;dis- matosis type 2. NEnglJMed.2009;361:358-367. cussion 1319-1320. 77. Mautner VF, Nguyen R, Kutta H, et al. Bevacizumab induces 61. Dombi E, Ardern-Holmes SL, Babovic-Vuksanovic D, et al. Rec- regression of vestibular schwannomas in patients with neurofibro- ommendations for imaging tumor response in neurofibromatosis matosis type 2. Neuro Oncol.2010;12:14-18. clinical trials. Neurology.2013;81:S33-S40. 78. Plotkin SR, Merker VL, Halpin C, et al. Bevacizumab for progres- 62. Cai W, Kassarjian A, Bredella MA, et al. Tumor burden in sive vestibular schwannoma in neurofibromatosis type 2: a retro- patients with neurofibromatosis types 1 and 2 and schwannoma- spective review of 31 patients. Otol Neurotol. 2012;33:1046-1052. tosis: determination on whole-body MR images. Radiology.2009; 79. Goutagny S, Raymond E, Sterkers O, Colombani JM, Kalamar- 250:665-673. ides M. Radiographic regression of cranial meningioma in a NF2 63. Slattery WH III, Fisher LM, Iqbal Z, Oppenhiemer M. Vestibu- patient treated by bevacizumab. Ann Oncol.2011;22:990-991. lar schwannoma growth rates in neurofibromatosis type 2 natu- 80. Farschtschi S, Merker VL, Wolf D, et al. Bevacizumab treatment ral history consortium subjects. Otol Neurotol.2004;25: for symptomatic spinal ependymomas in neurofibromatosis type 811-817. 2. Acta Neurol Scand.2016;133:475-480. 64. Fisher LM, Doherty JK, Lev MH, Slattery WH. Concordance of 81. Karajannis MA, Legault G, Hagiwara M, et al. Phase II trial of bilateral vestibular schwannoma growth and hearing changes in lapatinib in adult and pediatric patients with neurofibromatosis neurofibromatosis 2: neurofibromatosis 2 natural history consor- type 2 and progressive vestibular schwannomas. Neuro Oncol. tium. Otol Neurotol.2009;30:835-841. 2012;14:1163-1170. 22 Journal of Child Neurology 32(1)

82. Plotkin SR, Albers AC, Babovic-Vuksanovic D, et al. Update 87. Slattery WH III, Fisher LM, Hitselberger W, Friedman RA, from the 2013 international neurofibromatosis conference. Am J Brackmann DE. Hearing preservation surgery for neurofibroma- Med Genet A.2014;164A:2969-2978. tosis type 2-related vestibular schwannoma in pediatric patients. J 83. MacNally SP, Rutherford SA, King AT, et al. Outcome from Neurosurg.2007;106:255-260. surgery for vestibular schwannomas in children. Br J Neurosurg. 88. Mathieu D, Kondziolka D, Flickinger JC, et al. Stereotactic radio- 2009;23:226-231. surgery for vestibular schwannomas in patients with neurofibro- 84. Jaaskelainen J, Paetau A, Pyykko I, Blomstedt G, Palva T, Troupp matosis type 2: an analysis of tumor control, complications, and H. Interface between the facial nerve and large acoustic neurino- hearing preservation rates. Neurosurgery.2007;60:460-468;dis- mas. Immunohistochemical study of the cleavage plane in NF2 cussion 468-470. and non-NF2 cases. JNeurosurg.1994;80:541-547. 89. Rowe JG, Radatz MW, Walton L, Soanes T, Rodgers J, Kemeny 85. Friedman RA, Goddard JC, Wilkinson EP, et al. Hearing preser- AA. Clinical experience with gamma knife stereotactic radiosur- vation with the middle cranial fossa approach for neurofibroma- gery in the management of vestibular schwannomas secondary to tosis type 2. Otol Neurotol.2011;32:1530-1537. type 2 neurofibromatosis. JNeurolNeurosurgPsychiatry.2003; 86. Neff BA, Wiet RM, Lasak JM, et al. Cochlear implantation in the 74:1288-1293. neurofibromatosis type 2 patient: long-term follow-up. Laryngo- 90. Baser ME, DG RE, Gutmann DH. Neurofibromatosis 2. Curr scope.2007;117:1069-1072. Opin Neurol.2003;16:27-33. Author's personal copy

Cancer Treatment Reviews 40 (2014) 857–861

Contents lists available at ScienceDirect

Cancer Treatment Reviews

journal homepage: www.elsevierhealth.com/journals/ctrv

Anti-Tumour Treatment Systemic therapy in neuroﬁbromatosis type 2

a, b,1 c,2 a,d,3 Stephanie Hui-Su Lim ⇑, Simone Ardern-Holmes , Geoffrey McCowage , Paul de Souza a Department of Medical Oncology and Ingham Research Institute, Liverpool, NSW, Australia b TY Nelson Department of Neurology and Neurosurgery, The Children’s Hospital at Westmead, Westmead, NSW, Australia c Oncology Research Unit, The Children’s Hospital at Westmead, Westmead, NSW, Australia d University of Western Sydney, School of Medicine, Molecular Medicine Research Group, NSW, Australia article info abstract

Article history: The systemic treatment of patients with neurofibromatosis type 2 associated tumours is challenging, as Received 8 May 2014 these patients often have prolonged survival but with the inevitable propensity for their disease to cause Accepted 9 May 2014 symptoms, and no effective therapies other than local treatments such as surgery. Understanding the molecular mechanisms driving NF-2 pathogenesis holds promise for the potential use of targeted therapy. Initial studies of agents such as bevacizumab (angiogenesis inhibitor) and lapatinib (epidermal Keywords: growth factor and ErbB2 inhibitor) have indicated benefit for selected patients. As the biology of NF-2 Neurofibromatosis type 2 is dependent on multiple interlinked downstream signalling pathways, targeting multiple pathways Signal transduction may be more effective than single agents. Phase zero trials, adaptive phase II or small multi-arm trials, Tyrosine kinase inhibitors are likely the way forward in this rare disease. Ideally, well-tolerated targeted therapy would appear to be the most promising approach for patients with NF-2, given the natural history of this disease. Ó 2014 Elsevier Ltd. All rights reserved.

Introduction has likely improved over time given the advances in diagnosis and treatment [5,6]. The distinctive clinical feature is the presence of Neurofibromatosis type 2 (NF-2) is an autosomal-dominant, bilateral vestibular schwannomas. Schwannomas also commonly multiple neoplasia syndrome resulting from a mutation in the occur on other cranial nerves, and along with intracranial meningi- NF-2 tumour suppressor gene on chromosome 22q12 [1]. It occurs omas, often multiple, affect about 50% of patients. Spinal tumours at an estimated incidence of 1:25,000 [2] to 1:33 000 [3] and has a occur in 63–90% of NF-2 patients and are heterogenous, consisting penetrance of nearly 100% by age 60. The course of the disease is of meningiomas, schwannomas and ependymomas. Posterior usually progressive, though variable, causing significant morbidity subcapsular lens opacities are the most common ocular findings associated with deafness, blindness, brain stem compression, gait [2,5,7,6]. The clinical diagnostic criteria consist of bilateral instability and paralysis. Onset typically occurs while a patient is vestibular schwannomas, or unilateral vestibular schwannoma in their 20s, but more than 40% die by the age of 50. Mean actuarial and two of the other distinct tumours, or either of these latter survival in a series from 1995 was 62 years of age [4]. Other reports two criteria in addition to family history or multiple meningiomas state survival ranges between 30 and 50 years of age, however this [6]. The development of novel medical therapy is targeted at vestibular schwannomas in the first instance, with recommendations for standardised response criteria in treatment trials Corresponding author. Address: Department of Medical Oncology, Ingham developed by an international team of experts in the Response ⇑ Research Institute, 1 Campbell St, Liverpool, NSW 2170, Australia. Tel.: +61 2 9616 Evaluation in Neurofibromatosis and Schwannomatosis (REiNS) 4407; fax: +61 2 9616 4499. collaboration [8]. E-mail addresses: [email protected] (S.H.-S. Lim), simone. [email protected] (S. Ardern-Holmes), geoff.mccowage@health. nsw.gov.au (G. McCowage), [email protected] (P. de Souza). 1 TY Nelson Department of Neurology and Neurosurgery, The Children’s Hospital at Differential diagnosis of NF-2 Westmead, Corner Hawkesbury Rd and Hainsworth St, Westmead, NSW 2145, Australia. Tel.: +61 2 9845 2551; fax: +61 2 9845 3905. The neurofibomatosis family of syndromes includes Neurofibro- 2 Department of Oncology, The Children’s Hospital at Westmead, Corner Hawkes- matosis Type 1 (NF-1), NF-2 and schwannomatosis [5]. NF-1 was bury Rd and Hainsworth St, Westmead, NSW 2145, Australia. Tel.: +61 2 9845 2141; fax: +61 2 9845 2171. clearly established as distinct from NF-2 in 1987 when it was 3 Department of Medical Oncology, Liverpool Hospital, Elizabeth St, Liverpool, NSW recognised as a different autosomal dominant disorder character- 2170, Australia. Tel.: +61 2 9616 4407; fax: +61 2 9616 4499. ised by subcutaneous and plexiform neurofibromas, café au lait http://dx.doi.org/10.1016/j.ctrv.2014.05.004 0305-7372/Ó 2014 Elsevier Ltd. All rights reserved. Author's personal copy

858 S.H.-S. Lim et al. / Cancer Treatment Reviews 40 (2014) 857–861 spots, intertriginous freckling, lisch nodules and optic pathway gli- neurofibrosarcomas and may respond to cyclophosphamide, vin- oma [9]. The main differential for NF-2 is schwannomatosis [10], cristine and doxorubicin. These reports predate the reclassification which is characterised by spinal, peripheral and cranial nerve sch- of neurofibromatosis and elucidation of the underlying genetic wannomas in the absence of vestibular schwannomas. It is a mutation in NF-2. The slowly proliferating nature of NF2-associated genetic disorder due to a mutation in tumour suppressor gene tumours would predict a low response to cytotoxic chemotherapy, INI1/SMARCB1, which is on the same chromosome as the causative which is typically expected to be more active on rapidly dividing mutation in NF-2 [11]. cells. However, the increasing understanding of the molecular mechanisms driving pathogenesis holds promise for the use and Molecular biology of NF-2 efficacy of targeted therapy. The initial focus is on treatment of vestibular schwannomas. NF-2 mutations are found in 93% of patients in the second gen- Given the slowly proliferating nature of schwannomas, and eration [10]. Around 50% inherit the mutation, the remainder being their inevitable propensity to cause symptoms, there is a strong de novo mutations. Tumorigenesis in NF-2 is thought to be second- need to find effective drug targets for this disease. Treating these ary to mutational inactivation and allelic loss of the NF-2 gene, as patients is challenging however, as they may have prolonged well as hypermethylation [12,13]. The specific type of mutation survival during which unanticipated delayed toxic effects of any may correlate with disease severity [14]. The NF-2 gene encodes therapy can manifest; further, patients are likely to require treat- Merlin, also called schwannomin, a tumour suppressor protein ment for prolonged periods of time, so low toxicity of therapy is [15]. It resembles moesin, ezrin and radixin-like proteins, is a priority for patients. associated with the hyaluronic acid receptor CD44 and mediates contact-dependent inhibition of proliferation. It also stabilises cadherin-containing junctions. Effects mediated by membrane Novel therapeutics organisation of proteins include cell-to-cell adhesion, cytoskeletal architecture, interaction with cytosolic proteins and regulation of Given the complexity of signalling pathways downstream of downstream pathways. Two isoforms of Merlin exist, namely I Merlin loss (Fig. 1), a number of potential therapeutic targets have and II [5]. Only isoform I is capable of tumour suppressor function. been proposed [22]. The ErbB family of receptor tyrosine kinases Merlin appears to regulate multiple signal transduction pathways, comprise Her-1, Her-2, Her-3 and Her-4. They mediate downstream and recent evidence suggests that it also has a role in suppressing signalling pathways including the Ras-Raf-MAPK/ERK kinase (MEK) the E3 ubiquitin ligase CRL4 (DCAF1) in the nucleus to inhibit cell pathway and the phosphatidylinositol 3-kinase (PI3 K) Akt-mam- proliferation [16]. However, its specific role is yet to be elucidated malian target of rapamycin (mTOR) pathway [15]. Neuregulin-1 [17]. The molecular biology of NF-2 is complex and beyond the (NRG1) and NRG2 are agonists of Her-3. In vivo studies demon- scope of our review. The role of inhibitors of selected pathways strated that NRG1, Her-2 and Her-3 are crucial for schwann cell is discussed below. development. Hence Her- family receptors may be relevant targets for schwannoma drug therapy. Trastuzumab, a Her-2 inhibitor, has been found to inhibit cell growth in vestibular schwannoma xeno- Clinical management grafts [23]. However, in human primary schwannoma cells, the Her-1/2 inhibitor lapatinib did not reduce basal activity of ERK1/2 The mainstay of treatment of NF-2 currently is surgery for and Akt or basal proliferation [15]. This suggests that autocrine symptomatic tumours. The indication and timing of surgery is release of growth factors other than NRG1, such as platelet derived unclear (reviewed by Blakeley et al. [18]). For vestibular schwan- growth factor (PDGF) or insulin-like growth factor (IGF), could be noma, surgery is complicated by the proximity of the vestibular more relevant in the pathophysiology. nerve to the facial and acoustic nerves, with risk of facial nerve Epidermal growth factor receptor (EGFR) antagonism has also palsy and complete hearing loss. Surgery may be considered as first been proposed as a potential therapy for schwannomas [24]. A case line therapy for vestibular schwannoma greater than 3 cm in diam- series of 11 patients who received erlotinib via compassionate eter without brainstem compromise or hydrocephalus [6,18]. access, reported that a subset of patients experienced tumour However, many cases are managed expectantly and debulking stabilisation [25]. All patients were poor surgical candidates, and performed on symptom progression. Tumours less than 3 cm 5 of these patients had experienced a growth rate of greater than may be excised, or managed expectantly. Radiotherapy treatment 60% in the last 12 months. The median time to progression is controversial in the treatment of schwannomas. A recent was 9.2 months and none of the patients achieved a radiological meta-analysis has shown greater tumour control rates for stereo- response. However, 27% of patients experienced stable disease, tactic radiation as compared to conservative management [19], indicating that erlotinib may have a cytostatic rather than a cyto- however there is insufficient evidence to make such a treatment toxic effect. Another study of inhibition of the Her-2/EGFR pathway recommendation for hearing preservation. Moreover, there is a was more successful, suggesting that lapatinib could be a useful definite increased risk of development of de novo malignant treatment [26]. In this trial of 21 enrolled patients, a 23.5% volu- gliomas and malignant progression of acoustic neuromas after metric response was achieved, as well as a 30.8% rate of hearing focused radiotherapy using stereotactic radiosurgery [20]. Hence improvement in 17 evaluable patients. micro-neurosurgical removal should be considered, even if the A recent phase II open-label study investigated the mTOR- procedure is subtotal to minimize risks to the seventh cranial inhibitor everolimus in 10 patients with NF-2 related vestibular nerve, especially in young patients who have become functionally schwannomas [27], with the primary outcome being objective deaf on that side [20]. response rate. None of the 9 patients who could be evaluated had a volumetric or hearing response. This is in line with in vitro Systemic therapies data supporting the cytostatic but not cytotoxic effect of inhibition of mTORC1 [28]. To date, cytotoxic chemotherapy has no established role in the These studies raise the question of whether time to progression, treatment of NF-2. Historical case reports of malignant schwanno- as opposed to response rate, would be a more appropriate end- mas have documented responses to chemotherapy in patients who point in this chronic disease [8,29]. The REiNS collaboration has develop pulmonary metastases [21]. These tumours are likely proposed the incorporation of functional and patient-related Author's personal copy

S.H.-S. Lim et al. / Cancer Treatment Reviews 40 (2014) 857–861 859

Fig. 1. Downstream signalling pathways involved in the pathogenesis of NF-2, with the drug targets shown in red. Abbreviations: EGFR = epidermal growth factor receptor; ERK1/2 = extracellular signal-regulated kinase 1/2; HSP = heat shock protein; IGF1R = insulin-like growth factor 1 receptor; MEK1/2 = MAPK (mitogen activated protein kinase)/ERK kinase 1/2; mTOR = mammalian target of rapamycin; PAK = p21-activated kinase; PDGF = platelet-derived growth factor; P13 K = phosphatidylinositol 3-kinase; PKC = protein kinase C; VEGF = vascular endothelial derived growth factor. Adapted from references [15,35,42]. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.) outcomes in clinical trials in NF-2 [30]. Whole body MRI has also and Akt [22] Curcumin, a polyphenol extracted from turmeric, has been investigated as a means of measuring tumour burden [31]. also been investigated as a potential drug in NF-2, given its ability IGF-I receptor signalling regulates growth and metabolism of to inhibit HSP90 [35]. It upregulates HSP90 in cell lines, including various organs and tissues during embryonal and postnatal develop- HEI-193 schwannoma cell lines. Hence, combination of curcumin ment [15]. In adult rodents, IGF-I and IGF-II are crucial for schwann and Hsp inhibitor KNK437 is synergistic [35]. However, curcumin cell development and survival. An IGF-IR inhibitor, picropodophyl- has limited bioavailability via the oral route, thereby limiting the lin, markedly inhibited IGF-I-mediated proliferation and adhesion clinical utility of this approach. of human primary schwannoma cells. None of these have been Schwannoma proliferation is dependent on ERK1/2 activation, tested in the clinic as yet. Inhibition of PDGFR and IGFIR might be basal and PDGF-DD-mediated activation of PDGFR-beta(b) and the most appropriate strategy for schwannoma treatment [15]. Akt [15]. Utilising multi-targeted therapy like sorafenib and niloti- One candidate target is PI3 K, which is involved in PDGFR-mediated nib may be expected to be effective [36]. Sorafenib has been shown ERK1/2 and Akt activation and could provide a common link. Over- to be more effective than selumetinib (AZD6244, a MEK inhibitor) activation of the Akt pathway has been hypothesised to result in and nilotinib in reducing schwannoma cell proliferation [37]. As Merlin phosphorylation and enhancement of its degradation via sorafenib differentially inhibits Raf over the other two drugs, it is the proteosome pathway [32]. The PI3 K-mTOR inhibitor BEZ235 surmised that Raf may be more important in NF-2 pathophysiol- significantly decreased basal proliferation and completely abro- ogy. However, use of sorafenib is limited by its toxicity profile. gated IGF-I-mediated proliferation in human primary schwannoma Given the benign character of these tumours, long-term therapy cells. OSU-03012 is a derivative of cyclooxygenase-2 inhibitor cele- is often necessary. A drug that may fit the criteria for tolerability coxib and inhibits PDK-1, which is an upstream kinase that phos- is imatinib. phorylates Akt. It has been shown to be effective in inducing Imatinib targets c-KIT and PDGF-b, which appear to be overex- apoptosis and inhibiting cellular proliferation in human schwan- pressed in NF-2, albeit perhaps not as significantly as in gastroin- noma cells [33]. Interestingly, OSU-03012 is able to facilitate anti- testinal stromal tumour (GIST). HEI-193 NF-2 null schwannoma proliferative effects in imatinib-resistant cells by suppressing Akt cells had decreased in vitro viability with imatinib in a dose-depen- phosphorylation [34]. p-21 activated kinase (PAK) inhibitors could dent manner [38], possibly through increased apoptosis. The act via direct blockage of growth factor dependent tumour cell authors concluded that this data would support the use of imatinib survival and reactivation of Merlin. Bio 30 with propolis from bee in clinical trials of human schwannomas; this has been demon- venom may act as a PAK inhibitor [22]. strated in a case report [39], albeit the response criteria should ide- As the biology of NF-2 is dependent on multiple interlinked ally be based on volumetric response [40]. downstream signalling pathways (Fig. 1), and as many of the drugs Nilotinib has also been evaluated in comparison with imatinib investigated thus far are multi-targeted, it is difficult to ascertain [37]. Both drugs effectively inhibit PDGF-DD–mediated PDGFR-b, whether there is one pathway which is more important in its path- ERK1/2, and Akt activation. Basal activity of those targets was also ogenesis. Thus, targeting multiple pathways may be more effective inhibited by both drugs, except for ERK1/2, which was inhibited than single agents. 17AAG is a compound that inhibits Heat Shock only by Nilotinib. Nilotinib is more effective than imatinib Protein 90 (HSP90) and therefore reduces the stability of ErbB, Raf in vitro, with a maximal inhibitory effect at a concentration 10-fold Author's personal copy

860 S.H.-S. Lim et al. / Cancer Treatment Reviews 40 (2014) 857–861 lower than that of imatinib. This difference in potency is likely due References to the higher cell-membrane permeability of nilotinib, which is more lipophilic and hence relies less on active transport mecha- [1] Rouleau GA, Merel P, Lutchman M, et al. Alteration in a new gene encoding a putative membrane-organizing protein causes neuro-fibromatosis type 2. nisms to enter cells. A low concentration of selumetinib in addition Nature 1993;363(6429):515–21 [Epub 1993/06/10]. to nilotinib resulted in a significant increase in the efficiency of nil- [2] Evans DG, Moran A, King A, et al. Incidence of vestibular schwannoma and otinib. This would suggest that inhibition of the MEK1/2/ERK1/2 neurofibromatosis 2 in the North West of England over a 10-year period: pathway is synergistic with inhibition of PDGFR in reducing higher incidence than previously thought. Otology & neurotology: official publication of the American Otological Society. Am Neurotol Soc Eur Acad Otol schwannoma proliferation. Neurotol 2005;26(1):93–7 [Epub 2005/02/09]. Other novel approaches include inhibition of histone deacetyl- [3] Evans DG, Howard E, Giblin C, et al. Birth incidence and prevalence of tumor- ase by AR42 [41], which induced apoptosis, inhibited phosphory- prone syndromes: estimates from a UK family genetic register service. Am J Med Genet Part A 2010;152A(2):327–32 [Epub 2010/01/19]. lated Akt, and inhibited growth of xenografts. [4] Evans DG, Huson SM, Donnai D, et al. A clinical study of type 2 neurofibromatosis. Quart J Med 1992;84(304):603–18 [Epub 1992/08/01]. [5] Asthagiri AR, Parry DM, Butman JA, et al. Neurofibromatosis type 2. Lancet Angiogenesis inhibitors 2009;373(9679):1974–86 [Epub 2009/05/30]. [6] Evans DG. Neurofibromatosis 2 [Bilateral acoustic neurofibromatosis, central neurofibromatosis, NF2, neurofibromatosis type II]. Genet Med: Off J Am Coll Targeting angiogenesis with the vascular endothelial growth Med Genet 2009;11(9):599–610 [Epub 2009/08/05]. factor (VEGF) monoclonal antibody bevacizumab or small mole- [7] Patronas NJ, Courcoutsakis N, Bromley CM, et al. Intramedullary and spinal cule VEGF inhibitors appears promising. Merlin loss may lead to canal tumors in patients with neurofibromatosis 2: MR imaging findings and downregulation of semaphorin 3F, which then promotes angiogen- correlation with genotype. Radiology 2001;218(2):434–42 [Epub 2001/02/13]. [8] Plotkin SR, Blakeley JO, Dombi E, et al. Achieving consensus for clinical trials: esis [42]; restoration of pro-angiogenic and anti-angiogenic func- the REiNS international collaboration. Neurology 2013;81(21 Suppl 1):S1–5 tions may therefore represent a rational approach to therapy. In [Epub 2013/11/28]. addition, VEGFR-2 expression has been demonstrated in 32% of [9] Neurofibromatosis. Conference statement. National institutes of health consensus development conference. Arch Neurol, vol. 45(5), 1988. p. 575–78. vessels in vestibular schwannomas [43]. The initial reports of hear- [Epub 1988/05/01]. ing improvement and tumour shrinkage with bevacizumab in a [10] Evans DG. Neurofibromatosis type 2 (NF2): a clinical and molecular review. small number of patients with vestibular schwannoma [43,44] Orphanet J Rare Dis 2009;4:16 [Epub 2009/06/24]. [11] Hulsebos TJ, Plomp AS, Wolterman RA, et al. Germline mutation of INI1/ was followed by review of 31 patients demonstrating sustained SMARCB1 in familial schwannomatosis. Am J Hum Genet 2007;80(4):805–10 response for up to 3 years [45]. Patients aged 12–73 years were [Epub 2007/03/16]. included with 57% of evaluable patients (13/23) showing improve- [12] Hung G, Faudoa R, Baser ME, et al. Neurofibromatosis 2 phenotypes and germline NF2 mutations determined by an RNA mismatch method and loss of ment in word recognition score, and 55% (17/31) showing at least heterozygosity analysis in NF2 schwannomas. Cancer Genet Cytogenet 20% tumour shrinkage, on a background of progressive growth. 2000;118(2):167–8 [Epub 2000/04/05]. Sustained hearing improvement was seen in 90% of patients after [13] Kino T, Takeshima H, Nakao M, et al. Identification of the cis-acting region in the NF2 gene promoter as a potential target for mutation and methylation- 1 year and 61% at 3 years; sustained radiologic response occurred dependent silencing in schwannoma. Genes Cells Dev Mol Cell Mech in 88% of patients at 1 year of treatment and 54% at 3 years. 2001;6(5):441–54. [14] Parry DM, MacCollin MM, Kaiser-Kupfer MI, et al. Germ-line mutations in the neurofibromatosis 2 gene: correlations with disease severity and retinal Conclusions abnormalities. Am J Hum Genet 1996;59(3):529–39 [Epub 1996/09/01]. [15] Ammoun S, Hanemann CO. Emerging therapeutic targets in schwannomas and other merlin-deficient tumors. Nat Rev Neurol 2011;7(7):392–9 [Epub 2011/ In NF-2, as in other rare diseases, identifying the most effective 06/08]. systemic therapy remains a challenging problem. Better understand- [16] Zhou L, Hanemann CO. Merlin, a multi-suppressor from cell membrane to the ing of the molecular pathways and utilisation of well-tolerated nucleus. FEBS Lett 2012;586(10):1403–8 [Epub 2012/05/19]. [17] Yohay KH. The genetic and molecular pathogenesis of NF1 and NF2. Semin targeted agents would appear to be the most promising approach. Pediatr Neurol 2006;13(1):21–6. However, the complexity of inter-related signalling pathways in [18] Blakeley JO, Evans DG, Adler J, et al. Consensus recommendations for current NF-2 pathogenesis suggests that multiple agents administered in treatments and accelerating clinical trials for patients with neurofibromatosis type 2. Am J Med Genet Part A 2011 [Epub 2011/12/06]. concert, rather than a single drug, may result in the most effective [19] Maniakas A, Saliba I. Conservative management versus stereotactic radiation therapy. On the other hand, an aggressive approach has to be for vestibular schwannomas: a meta-analysis of patients with more than 5 weighed up against potential toxicity, given the slow growth of years’ follow-up. Otology & neurotology: official publication of the American schwannomas and prolonged survival of patients with NF-2. In Otological Society. Am Neurotol SocEur Acad Otol Neurotol 2012;33(2):230–8 [Epub 2012/01/10]. the absence of cure, a reasonable goal may be early symptomatic [20] Balasubramaniam A, Shannon P, Hodaie M, et al. Glioblastoma multiforme treatment or pre-symptomatic treatment in familial cases, to after stereotactic radiotherapy for acoustic neuroma: case report and review of achieve maintenance of stable disease. Translational clinical studies the literature. Neuro-Oncol 2007;9(4):447–53 [Epub 2007/08/21]. [21] Goldman RL, Jones SE, Heusinkveld RS. Combination chemotherapy of in small numbers of patients to explore the pharmacokinetics and metastatic malignant schwannoma with vincristine, adriamycin, cyclo- pharmacodynamics of targeted therapies based on molecular char- phosphamide, and imidazole carboxamide: a case report. Cancer 1977;39(5): acterisation, or Phase zero trials could be helpful. Alternatively, an 1955–8 [Epub 1977/05/01]. [22] Evans DG, Kalamarides M, Hunter-Schaedle K, et al. Consensus recom- international multi-centre cooperative approach to the conduct of mendations to accelerate clinical trials for neurofibromatosis type 2. Clin adaptive phase II trials or small multi-arm trials [18] rather than Cancer Res: Off J Am Assoc Cancer Res 2009;15(16):5032–9 [Epub 2009/08/13]. traditional phase III placebo-controlled trials, could be used to seek [23] Clark JJ, Provenzano M, Diggelmann HR, et al. The ErbB inhibitors trastuzumab and erlotinib inhibit growth of vestibular schwannoma xenografts in nude regulatory approvals for new therapies in this rare tumour suppres- mice: a preliminary study. Otology & neurotology : official publication of the sor syndrome. American Otological Society. Am Neurotol Soc Eur Acad Otol Neurotol 2008;29(6):846–53 [Epub 2008/07/19]. [24] Plotkin SR, Singh MA, O’Donnell CC, et al. Audiologic and radiographic Conflict of interest response of NF2-related vestibular schwannoma to erlotinib therapy. Nat Clin Pract Oncol 2008;5(8):487–91 [Epub 2008/06/19]. [25] Plotkin SR, Halpin C, McKenna MJ, et al. Erlotinib for progressive vestibular Professor De Souza is on advisory boards for Janssen, Sanofi and schwannoma in neurofibromatosis 2 patients. Otology & neurotology: official Astellas Pharmaceuticals, Australia. Dr. Ardern-Holmes has served publication of the American Otological Society. Am Neurotol Soc Eur Acad Otol on a scientific advisory board for Novartis Pharmaceuticals Austra- Neurotol 2010;31(7):1135–43. [26] Karajannis MA, Legault G, Hagiwara M, et al. Phase II trial of lapatinib in adult and lia and receives research support from The Children’s Tumour pediatric patients with neurofibromatosis type 2 and progressive vestibular Foundation of Australia. schwannomas. Neuro-Oncol 2012;14(9):1163–70 [Epub 2012/07/31]. Author's personal copy

S.H.-S. Lim et al. / Cancer Treatment Reviews 40 (2014) 857–861 861

[27] Karajannis MA, Legault G, Hagiwara M, et al. Phase II study of everolimus in [36] Ammoun S, Flaiz C, Ristic N, Schuldt J, Hanemann CO. Dissecting and targeting children and adults with neurofibromatosis type 2 and progressive vestibular the growth factor-dependent and growth factor-independent extracellular schwannomas. Neuro-Oncol 2013 [Epub 2013/12/07]. signal-regulated kinase pathway in human schwannoma. Cancer Res [28] Lopez-Lago MA, Okada T, Murillo MM, Socci N, Giancotti FG. Loss of the tumor 2008;68(13):5236–45 [Epub 2008/07/03]. suppressor gene NF2, encoding merlin, constitutively activates integrin- [37] Ammoun S, Schmid MC, Triner J, Manley P, Hanemann CO. Nilotinib alone or in dependent mTORC1 signaling. Mol Cell Biol 2009;29(15):4235–49 [Epub combination with selumetinib is a drug candidate for neurofibromatosis type 2009/05/20]. 2. Neuro-Oncol 2011;13(7):759–66 [Epub 2011/07/06]. [29] Gutmann DH, Blakeley JO, Korf BR, Packer RJ. Optimizing biologically targeted [38] Mukherjee J, Kamnasaran D, Balasubramaniam A, et al. Human schwannomas clinical trials for neurofibromatosis. Expert Opin Investig Drugs express activated platelet-derived growth factor receptors and c-kit and are 2013;22(4):443–62 [Epub 2013/02/22]. growth inhibited by Gleevec (Imatinib Mesylate). Cancer Res [30] Widemann BC, Blakeley JO, Dombi E, et al. Conclusions and future directions 2009;69(12):5099–107 [Epub 2009/06/11]. for the REiNS international collaboration. Neurology 2013;81(21 Suppl [39] Lim S, de Souza P. Imatinib in neurofibromatosis type 2. BMJ Case Rep 2013 1):S41–4 [Epub 2013/11/28]. [Epub 2013/07/11]. [31] Plotkin SR, Bredella MA, Cai W, et al. Quantitative assessment of whole-body [40] Harris GJ, Plotkin SR, Maccollin M, et al. Three-dimensional volumetrics for tumor burden in adult patients with neurofibromatosis. PloS One tracking vestibular schwannoma growth in neurofibromatosis type II. 2012;7(4):e35711 [Epub 2012/05/05]. Neurosurgery 2008;62(6) [discussion 9-20. Epub 2008/10/01]. [32] Laulajainen M, Muranen T, Nyman TA, Carpen O, Gronholm M. Multistep [41] Bush ML, Oblinger J, Brendel V, et al. AR42, a novel histone deacetylase phosphorylation by oncogenic kinases enhances the degradation of the inhibitor, as a potential therapy for vestibular schwannomas and NF2 tumor suppressor merlin. Neoplasia 2011;13(7):643–52 [Epub 2011/ meningiomas. Neuro-Oncol 2011;13(9):983–99 [Epub 2011/07/23]. 07/14]. [42] Wong HK, Lahdenranta J, Kamoun WS, et al. Anti-vascular endothelial growth [33] Lee TX, Packer MD, Huang J, et al. Growth inhibitory and anti-tumour activities factor therapies as a novel therapeutic approach to treating neurofibromatosis- of OSU-03012, a novel PDK-1 inhibitor, on vestibular schwannoma and related tumors. Cancer Res 2010;70(9):3483–93 [Epub 2010/04/22]. malignant schwannoma cells. Eur J Cancer 2009;45(9):1709–20 [Epub 2009/ [43] Plotkin SR, Stemmer-Rachamimov AO, Barker 2nd FG, et al. Hearing 04/11]. improvement after bevacizumab in patients with neurofibromatosis type 2. [34] Tseng PH, Lin HP, Zhu J, et al. Synergistic interactions between imatinib mesylate New England J Med 2009;361(4):358–67 [Epub 2009/07/10]. and the novel phosphoinositide-dependent kinase-1 inhibitor OSU-03012 in [44] Mautner VF, Nguyen R, Kutta H, et al. Bevacizumab induces regression of overcoming imatinib mesylate resistance. Blood 2005;105(10):4021–7 [Epub vestibular schwannomas in patients with neurofibromatosis type 2. Neuro- 2005/01/25]. Oncol 2010;12(1):14–8 [Epub 2010/02/13]. [35] Angelo LS, Wu JY, Meng F, et al. Combining curcumin (diferuloylmethane) and [45] Plotkin SR, Merker VL, Halpin C, et al. Bevacizumab for progressive vestibular heat shock protein inhibition for neurofibromatosis 2 treatment: analysis of schwannoma in neurofibromatosis type 2: a retrospective review of 31 patients. response and resistance pathways. Mol Cancer Ther 2011;10(11):2094–103 Otology & neurotology: official publication of the American Otological Society. [Epub 2011/09/10]. Am Neurotol Soc Eur Acad Otol Neurotol 2012;33(6):1046–52. Hearing and facial function outcomes for neurofibromatosis 2 clinical trials

Scott R. Plotkin, MD ABSTRACT PhD Objectives: Vestibular schwannomas are the hallmark of neurofibromatosis 2 (NF2), occurring in Simone L. Ardern- .95% of patients. These tumors develop on the vestibulocochlear nerve and are associated with Holmes, MD significant morbidity due to hearing loss, tinnitus, imbalance, facial weakness, and risk of early Fred G. Barker II, MD mortality from brainstem compression. Although hearing loss and facial weakness have been Jaishri O. Blakeley, MD identified as important functional outcomes for patients with NF2, there is a lack of consensus D. Gareth Evans, MD regarding appropriate endpoints in clinical trials. Rosalie E. Ferner, MD Methods: The functional outcomes group reviewed existing endpoints for hearing and facial func- Tessa A. Hadlock, MD tion and developed consensus recommendations for response evaluation in NF2 clinical trials. Chris Halpin, PhD For the REiNS Results: For hearing endpoints, the functional group endorsed the use of maximum word recogni- International tion score as a primary endpoint, with the 95% critical difference as primary hearing outcomes. Collaboration The group recommended use of the scaled measurement of improvement in lip excursion (SMILE) system for studies of facial function. Conclusions: These recommendations are intended to provide researchers with a common set of Correspondence to endpoints for use in clinical trials of patients with NF2. The use of common endpoints should Dr. Plotkin: [email protected] improve the quality of clinical trials and foster comparison among studies for hearing loss and facial weakness. Neurology® 2013;81 (Suppl 1):S25–S32

GLOSSARY AAO-HNS 5 American Academy of Otolaryngology-Head and Neck Surgery; HB 5 House-Brackmann; HR 5 hearing response; NF2 5 neurofibromatosis 2; PTA 5 pure-tone average; REiNS 5 Response Evaluation in Neurofibromatosis and Schwannomatosis; SH 5 stable hearing; SMILE 5 scaled measurement of improvement in lip excursion; VS 5 vestibular schwannoma; WRS 5 word recognition score.

Vestibular schwannomas (VS) are the hallmark of neurofibromatosis 2 (NF2), occurring in .95% of patients. VS develop on the vestibulocochlear nerve and cause significant morbidity due to hearing loss, tinnitus, imbalance, and risk of early mortality from brainstem compression. Hearing loss develops over time in patients with NF2, and these declines are associated with gradual VS growth.1 Facial weakness is a common sequela of surgery to remove VS and may also occur as a late manifestation of large VS, secondary to facial nerve schwannomas, or as an isolated mononeuropathy.1 Facial weakness causes articulation difficulties, oral incompetence, lack of ability to smile and express emotions, and inability to blink and protect the cornea, which can lead to vision loss. Facial weakness and hearing loss adversely affect quality of life2–4 and as such represent important functional outcomes in clinical trials.

NATURAL HISTORY OF HEARING LOSS AND FACIAL WEAKNESS IN NF2 The natural history of hearing loss in NF2 has been studied in the prospective multicenter NF2 Natural History Study sponsored by the Department of Defense Consortium.5 In a cohort of 63 patients (108 VS) within 2 years of the diagnosis of NF2, 27% of the ears experienced a significant loss in pure-tone average, defined as a change of 5 dB Supplemental data at compared with baseline.5 The natural history of facial weakness in NF2 has not been well studied. The best data www.neurology.org From the Neurology Department and Cancer Center (S.R.P.) and Neurosurgical Service (F.G.B.), Massachusetts General Hospital, Boston, MA; Department of Neurology and Neurosurgery (S.L.A.-H.), The Children’sHospitalatWestmead,UniversityofSydney,Australia;DepartmentofNeurologyandOncology (J.O.B.), John Hopkins Medical Institute, Baltimore, MD; University Department of Medical Genetics (D.G.E.), St Mary’sHospital,Manchester,UK; Department of Neurology (R.E.F.), Guy’sandSt.Thomas’ NHS Foundation Trust and Institute of Psychiatry, King’sCollegeLondon,UK;Departmentof Otolaryngology (T.A.H.) and Audiology (C.H.), Massachusetts Eye and Ear Infirmary; and Harvard Medical School (T.A.H.), Boston, MA. REiNS International Collaboration members are listed on the Neurology® Web site at www.neurology.org. Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.

©2013AmericanAcademyofNeurology S25 come from large retrospective studies of facial function recognition scores (WRS), also known as speech rec- after resection of NF2-related VS. These studies suggest ognition scores or speech discrimination scores. Pure- that preoperative tumor size does not correlate with tone thresholds measure the minimum sound level facial function after middle fossa approach or transla- that an ear can perceive. Thresholds are typically mea- byrinthine approach.6,7 sured at octaves and half-octaves from 250 Hz to Consensus endpoints to study hearing loss and facial 8,000 Hz. An average of thresholds at 500, 1,000, weakness in the setting of NF2 are necessary. Currently, 2,000, and 4,000 Hz (pure-tone average [PTA]) is a there is no standard definition of hearing loss or facial recommended standard outcome measure for report- weakness that is used uniformly across clinical trials. ing in cases of VS.8 WRS measure the ability of pa- The lack of consensus makes it difficult to compare re- tients to meaningfully interpret sounds. WRS are sults between trials or between clinical reports of surgical measured as the percentage of monosyllables patients outcomes. The NF community would benefit from the can correctly identify when they are presented at a use of consensus definitions in future trials, particularly fully audible level. Paradoxically, WRS sometimes those that will be presented to national regulatory bodies decrease in individuals with VS when the words are as evidence for drug approval. presented at high volume (rollover effect).9 Standard audiologic techniques have been developed to avoid

MEASUREMENT OF HEARING LOSS AND FACIAL potential pitfalls in testing patients with retrocochlear WEAKNESS Hearing is monitored in clinical prac- lesions that exhibit rollover. Patients can be classified tice by measuring pure-tone thresholds and word into categories of hearing based on American Academy of Otolaryngology-Head and Neck Surgery (AAO- HNS) schemes: class A (PTA # 30, WRS .70%), Table 1 Grading of facial strength using the House-Brackmann scale10 class B (PTA .30 to # 50, WRS $ 50%), class C

Grade Description Characteristics (PTA .50, WRS $ 50%), and class D (PTA any , I Normal Normal facial function in all areas level, WRS 50%). Class A and B hearing are termed “serviceable”; class C and D hearing are termed “non- II Mild dysfunction Gross: slight weakness noticeable on close inspection; may have very slight synkinesis serviceable.”

At rest: normal symmetry and tone In clinical practice, facial function is monitored using the House-Brackmann (HB) scale,10 which Motion grades facial function in 6 steps from normal (HB Forehead: moderate to good function I) to total paralysis (HB VI) (table 1). In 1985, the Eye: complete closure with minimum effort AAO-HNS adopted the HB as a universal standard. Mouth: slight asymmetry Over the years, the HB grading scale has been up- III Moderate Gross: obvious but not disfiguring difference between 2 sides; dated.11 Other scales, such as Burres-Fisch, Notting- dysfunction noticeable but not severe synkinesis, contracture, and/or hemifacial spasm ham, Sunnybrook, and Yanagihara, have also been 12 At rest: normal symmetry and tone used to grade facial function.

Motion METHODS The Response Evaluation in Neurofibromatosis Forehead: slight to moderate movement and Schwannomatosis (REiNS) functional outcomes group was Eye: complete closure with effort formed to address the lack of consensus about appropriate functional endpoints to use in NF clinical trials. The functional out- Mouth: slightly weak with maximum effort comes group has 10–15 active participants that meet monthly for IV Moderately severe Gross: obvious weakness and/or disfiguring asymmetry teleconferences and present recommendations biannually to the dysfunction full REiNS International Collaboration group. The group con- At rest: normal symmetry and tone sists of professionals from various disciplines involved in NF care,

Motion including neurologists, geneticists, otolaryngologists, audiologists, oncologists, therapists, radiologists, and statisticians. The Forehead: none group has representation from the US, Europe, and Australia. Eye: incomplete closure Selection of functional endpoints. During the first meeting, Mouth: asymmetric with maximum effort the functional endpoint group agreed to discuss 4 functional end- V Severe dysfunction Gross: only barely perceptible motion points that were relevant for patients with NF1, NF2, and schwannomatosis as part of a clinical trial: 1) hearing function, At rest: asymmetry 2) facial function, 3) walking function, and 4) pulmonary func- Motion tion. We report the first 2 endpoints assessed by the functional Forehead: none endpoints working group.

Eye: incomplete closure Rating of functional endpoints. The functional outcomes Mouth: slight movement group modified the standardized form used for patient-reported outcomes (see Wolters et al., this supplement). Using this form, VI Total paralysis No movement the group reviewed outcome measures for hearing function and

S26 Neurology 81 (Suppl 1) November 19, 2013 facial function. For hearing function, the review included use of language.8 There are also valid tests that can be re- PTA, AAO-HNS hearing classification,13 the Gardner-Robertson ported using the same mathematical criteria available 14 hearing classification, and the 95% critical difference for word in several languages.21 recognition.15 For facial function, the group reviewed use of the Use in published studies. The 95% critical difference HB scale11,16 and the scaled measurement of improvement in lip excursion (SMILE) analysis.17 has been used as a primary endpoint or as a secondary endpoint in studies of sudden sensorineural hearing loss15 and in studies of bevacizumab and lapatinib RESULTS For hearing endpoints, the functional for NF2-related VS.22–24 group chose to endorse the use of maximum WRS Baseline documentation of “target” and “nontarget” as a primary endpoint, with the 95% critical differ- lesions. When 2 functional ears are present at baseline, ence for primary hearing outcomes15 and the SMILE the target ear and nontarget ear should be identified system for facial outcomes.18 These outcomes are dis- and recorded at baseline. The goal is to target an cussed below. ear that lends itself to reproducible repeated measures. Recommended primary outcome for hearing: Maximum Target ears should be selected on the basis of the qual- WRS. Hearing in patients with NF2 is measured using ity of the hearing and the presence of an ipsilateral an audiogram that includes measurement of pure- VS. Hearing loss in the target ear should be attributed tone thresholds and WRS. Word recognition is the to VS (rather than other causes of hearing loss). measure most closely associated with daily hearing The maximum WRS should be recorded for all function since it measures the ability to comprehend ears. To address rollover, an empirical search using speech (rather than “detect” it). If word recognition at least 2 levels (“high” and “low”) should be used quality improves, the patient can converse success- to identify maximum WRS at each evaluation. fully, even if a hearing aid is needed to make sounds Speech intelligibility should be evaluated for each sufficiently loud. ear using standard word recognition of monosyl- Different statistical models have been used in clin- lables.25 All tests should use recorded lists (e.g., ical trials to compare 2 word recognition tests (as in a CID-W22, Ira Hirsh recording, Q/MASS v 2) from within-subject change with treatment). The use of a a compact disc26 rather than spoken word lists since fixed criterion for significance (e.g., a difference of this results in less variability of results. The initial 15 percentage points from baseline) is attractive given level should be set where maximum performance is the simplicity of implementing this rule. However, a expected for each ear. The “high” level will be the fixed criterion could allow certain errors, in that level calculated for maximum audibility, as in the changes that exceed the criterion might not be signif- standard method for level setting in nontumor cases. icant at p 5 0.05 (false-positive) and changes that are The “low” level will be the maximum level minus 10– less than the criterion might be significant at p 5 15 dB as chosen by the audiologist to reflect a level 0.05. If instead the significance level is fixed at with less chance of rollover. The maximum WRS is 0.05, the criterion for difference varies depending defined as the greater WRS determined at the “high” on the baseline WRS. This results in 2 scores, 1 above and “low” levels. and 1 below the starting value, which are known as Response criteria. Hearing response criteria are the critical differences at the selected probability level defined in reference to the baseline WRS at study ini- (i.e., p 5 0.05, table 2).15 tiation (table 2). Hearing response (HR) is defined as Feasibility. Audiology is widely available and it an improvement in WRS above the 95% critical dif- takes about 20 minutes to perform testing that ference. Stable hearing (SH) is defined as persistence includes a 50-word recognition list. Standardization of WRS within the 95% critical difference. Hearing of testing is critical for use in clinical trials. For this decline is defined as a decrease in WRS below the reason, the group recommends use of a recorded list 95% critical difference. of standardized monosyllables. Special notes on assessment of hearing. WRS is not a Patient characteristics. Standard audiometry can be continuous variable: it is a sum of binary responses administered reliably to individuals aged 5 years and (correct/incorrect) that ranges from 0% to 100%. The older.19 Audiometry is valid for important subgroups existence of upper and lower boundaries introduces a such as the elderly and people with intellectual disa- “ceiling” and “floor” effect for patients with hearing bility.20 Since the results are analyzed as repeated near the top and bottom of the range, respectively. As measures, a participant may be evaluated using table 2 shows, patients with WRS # 6% are not eligible English materials if the audiologist decides that the for hearing decline since the 95% critical difference results reasonably reflect comparative (test-to-test) includes 0%; similarly, patients with WRS $94% are performance. A recommended approach may be to not eligible for hearing improvement since the 95% require that participants be “testable in English” as critical difference includes 100%. In the NF2 Natural opposed to the narrower criterion of English as a first History study, the rate of spontaneous increase in WRS

Neurology 81 (Suppl 1) November 19, 2013 S27 was 16% in patients with baseline WRS $ 90%.27 For Table 2 Hearing response guidelines trials using hearing response as the primary outcome,

Baseline word 95% critical Hearing Progressive the functional group recommends excluding patients recognition score (%) difference (%) response (%) hearing loss (%) with WRS $ 90% to allow for appreciation of hearing 0 0–4 $6 n/a improvement and to ensure that test-to-test variation 2 0–10 $12 n/a does not obscure true changes in hearing function.

4 0–14 $16 n/a Frequency of reevaluation. No evidence-based guidelines are available to help determine the interval 6 2–18 $20 0 between evaluations. The functional group recom- 8 2–22 $24 0 mends reevaluation of maximum WRS every 3 10 2–24 $26 0 months during initial treatment and every 3–6 12 4–26 $28 #2 months during prolonged treatment. 14 4–30 $32 #2 Confirmatory measurement/duration of response. In

16 6–32 $34 #4 nonrandomized trials where response is the primary

18 6–34 $36 #4 endpoint, confirmation of response is desirable. The time between audiograms should be at least 1 month. 20 8–36 $38 #6 Responses that are not confirmed by subsequent 22 8–40 $42 #6 audiology should be termed “unconfirmed response.” 24 10–42 $44 #8 For randomized trials or for trials where time to hear- 26 12–44 $46 #10 ing decline is the primary endpoint, confirmation of 28 14–46 $48 #12 response is not required. To declare stable disease,

30 14–48 $50 #12 audiograms must show stable disease at least once after study initiation for a period of time that is 32 16–50 $52 #14 defined by the study protocol (usually 6 months). 34 18–52 $54 #16 Duration of hearing response. The duration of HR is 36 20–54 $56 #18 measured from the time when study measurement 38 22–56 $58 #20 first shows a HR until the first date that maximum 40 22–58 $60 #20 WRS is recorded within the 95% critical difference

42 24–60 $62 #22 of the baseline WRS. Duration of stable hearing. 44 26–62 $64 #24 SH is measured from the start of treatment until the criteria for hearing decline 46 28–64 $66 #26 are met, taking as reference the 95% critical differ- 48 30–66 $68 #28 ence of the baseline maximum WRS. For protocols 50 32–68 $70 #30 designed to study the proportion of patients with 52 34–70 $72 #32 SH for a minimum period of time, the protocol

54 36–72 $74 #34 should specify the interval between audiograms.

56 38–74 $76 #36 It is important to note that the duration of HR/ SH and the determination of time to hearing decline 58 40–76 $78 #38 is influenced by the frequency of follow-up after base- – 60 42 78 $80 #40 line evaluation. These intervals should be defined in 62 44–78 $80 #42 the study protocol. 64 46–80 $82 #44 Proportion free from hearing loss. Historically, most 66 48–82 $84 #46 patients with NF2 experience profound bilateral hear-

68 50–84 $86 #48 ing loss during the course of life. For young patients and those with good hearing, a therapy that could 70 52–86 $88 #50 prevent hearing loss would be desirable, even if this 72 54–86 $88 #52 therapy did not improve hearing. In this scenario, 74 56–88 $90 #54 the proportion of patients free from hearing loss at 76 58–90 $92 #56 landmark time points might be considered appropri- 78 60–92 $94 #58 ate to provide an initial sign of biologic activity. How-

80 64–92 $94 #62 ever, in uncontrolled phase II trials this endpoint is

82 66–94 $96 #64 subject to bias from known and unknown factors that influence hearing loss. Ideally, this endpoint is best 84 68–94 $96 #66 evaluated in the setting of a randomized trial. In the 86 70–96 $98 #68 case of NF2, spontaneous hearing improvement is Continued sufficiently uncommon (about 16% for patients with

S28 Neurology 81 (Suppl 1) November 19, 2013 tones29 due to cochlear and neural alterations.30 Fur- Table 2 Continued thermore, patients’ quality of life is directly limited by Baseline word 95% critical Hearing Progressive reduced word recognition rather than audibility, recognition score (%) difference (%) response (%) hearing loss (%) which can be addressed by amplification. For this 88 74–96 $98 #72 reason, the committee does not endorse changes in 90 76–98 100 #74 PTA as a primary outcome for hearing trials but does 92 78–98 100 #76 recommend that PTA be recorded as a secondary

94 82–98 100 #80 outcome.

96 86–100 n/a #84 Recommended primary outcome for facial function: 98 90–100 n/a #88 SMILE analysis. SMILE analysis is a technique to mea-

100 96–100 n/a #94 sure facial function that relies on computerized measurement of facial excursion based on photographs Abbreviation: n/a 5 not applicable. taken in standard positions (figure). The system uses Clinical criteria for definition of hearing response based on a 50-item monosyllable word recognition test. Upper and lower limits for the 95% critical differences for percentage the iris diameter (corneal white-to-white diameter) as a scores are adapted from Thornton.35 scale reference for all facial dimensions on the same photograph. This built-in scale—in the same plane as the oral commissure—allows measurements of hor- baseline WRS , 90%) that a nonrandomized trial izontal to vertical commissure excursion to be extrap- may be justifiable.27 olated from frontal photographs using readily available Reporting best response results. For phase II trials, all photo-editing software. patients in the study must be included in the report Feasibility. SMILE analysis is performed using frontal of the results, even those who are not evaluable or photographs of the patient at rest and with a full smile. experience major protocol deviations. Patients should Photos are imported into the software program (Face- be designated as either HR, SH, hearing decline, or gram), which then calculates an objective analysis of not evaluable (e.g., early death, toxicity, assessment smile symmetry and change in commissure excursion. not performed). In general, the denominator for cal- The Java-based SMILE analysis program is free for use culation of the response rate should include all eligible and can be downloaded at www.sircharlesbell.org/ patients. Conclusions should not be based on selected facial_nerve_programs.html. Complete facial analysis “evaluable” patients. For phase III trials, hearing takes less than 5 minutes and may be stored response evaluation may be a primary or secondary electronically for future use. endpoint. If hearing response evaluation is a primary Patient characteristics and validity. SMILE analysis can endpoint (i.e., the study includes only patients who be reliably performed in individuals capable of standard are capable of hearing improvement), the discussion facial poses.17 The lower age limit for reliability of mea- above should apply. If response evaluation is a sec- surement has not been determined. In a previous study ondary endpoint (i.e., the study includes all patients of 10 normal individuals (20 hemi-smiles), there was a regardless of hearing), the hearing response rate may strong correlation between measured distances and the be reported using an “intention-to-treat” analysis true excursion (class correlation coefficients R 5 0.96– (with all randomized patients in the denominator) 0.99). There was strong correlation between the meas- or using a predefined subset analysis (including the urements of excursion distances for multiple raters subset of patients with hearing loss at baseline). The (intraclass correlation coefficients: R 5 0.88–0.98). study protocol should specify how response results The intratest reliability after 1 week (for a given rater) will be reported, including any planned subset was 0.99, indicating a strong correlation between meas- analyses. urements over time. Other outcomes for hearing: Pure-tone average. An alter- Use in published studies. SMILE analysis has been native measure of hearing includes simple detection used as an endpoint in studies of facial reanimation of sound (i.e., the threshold of audibility). Pure-tone due to many causes, including NF2.31,32 To date, thresholds are most often measured at the frequencies the technique has not been used in multicenter of 250, 500, 1,000, 2,000, 3,000, 4,000, 6,000, and studies. 8,000 Hz. The PTA is calculated as the average of Baseline documentation of “target” and “nontarget” thresholds at 500, 1,000, 2,000, and 4,000 Hz,8 hemi-smiles. When unilateral facial weakness is present although other thresholds may be used.28 Changes at baseline, the target hemi-smile should be identified in pure-tone audiometry have been used in oncology and recorded at baseline. In this instance, the contra- studies to monitor ototoxicity from chemotherapy. lateral (nontarget) hemi-smile acts as a normal control However, in patients with VS, word recognition is for the affected side. A history of previous surgery that affected to a greater extent than detection of pure might affect facial strength (e.g., resection of VS)

Neurology 81 (Suppl 1) November 19, 2013 S29 such as keratopathy. SMILE analysis of facial photos Figure Example of SMILE analysis is capable of measuring corneal exposure before and after intervention. Measuring changes in lagophthal- mos should be studied with a goal of defining response criteria in the future. Presently, the group recommends a 2-mm increase in lid position as a functional response and a 2-mm decrease in lid position as functional decline. Frequency of reevaluation. No evidence-based guidelines are available to determine an appropriate interval between evaluations. The functional group recommends reevaluation of true smile excursion every 3 months during the first year after surgical intervention and yearly afterwards. Confirmatory measurement/duration of response. In nonrandomized trials where response is the primary endpoint, confirmation of response is desirable. The minimum time between facial analyses should be at least 1 month. Responses not confirmed by subsequent facial photos are termed “unconfirmed response.” For randomized trials or for trials where time to facial weakness is the primary endpoint, confirmation of response is not required. To declare stable facial strength, facial photos must show stable strength at least once after intervention at a time that should be recorded. When bifacial weakness is pre- is defined by the study protocol. sent at baseline, a target hemi-smile should be identi- Duration of facial response. The duration of facial fied and recorded at baseline, based on normative response is measured from the time when study mea- 33 smile parameters. surement first shows a facial response until the first Patients should be photographed using at least 2 date that facial photos demonstrate progressive facial facial poses, including “at rest” and with a broad weakness compared to the best change in true smile smile. Using the software, the true smile excursion excursion. from midline and the smile angle from horizontal Duration of stable facial function. Stable facial func- midline should be recorded for target and nontarget tion is measured from the start of treatment or inter- hemi-smiles (figure). Comparison between smile an- vention until the criteria for progressive facial gles and smile excursion on the normal side and the weakness are met, taking as reference the true smile affected side at baseline provides an objective analysis excursion at baseline. For protocols designed to study of smile symmetry. Comparison between smile angles the proportion of patients with stable facial function and smile excursion of the target hemi-smile before for a minimum period of time, the protocol should and after intervention provides an objective analysis specify the interval between facial photos. of change in commissure excursion with treatment. The duration of smiling response/stable facial Response criteria. Consensus criteria using SMILE function and the determination of time to progressive analysis (or other facial rating scales) have not been facial weakness are influenced by the frequency of defined to date. Until more data are acquired, the follow-up after baseline evaluation. These intervals functional committee proposes to define a response should be defined in the study protocol. as an increase in true smile excursion of 25% com- Proportion free from progressive facial weakness. Histor- pared with the true smile excursion at baseline. Pro- ically, patients with NF2 experience some facial weak- gression is defined as a decrease in true smile ness over their lifetime. For patients with normal excursion of 25% compared with the baseline true facial function, a novel procedure or technique smile excursion. Stable function is defined as all other (e.g., surgery or radiation) that minimizes, delays, or changes in true smile excursion compared with base- otherwise prevents facial weakness would be desir- line. These response criteria apply to patients with able. In this scenario, the proportion of patients free both unilateral facial weakness and bifacial weakness. from progressive facial weakness at landmark time Special notes on assessment of facial function. Patients points could be an appropriate measure of successful with facial weakness also experience paralytic lagoph- intervention. However, in uncontrolled phase II trials thalmos, which can increase risk of complications this endpoint is subject to bias from known and

S30 Neurology 81 (Suppl 1) November 19, 2013 unknown factors that influence facial function. Ide- of data. TA Hadlock: revising the manuscript for content, study concept, ally, this endpoint is best evaluated in the setting of interpretation of data. C Halpin: drafting the manuscript, study concept, interpretation of data. a randomized trial.

Reporting best response results. For phase II trials, all ACKNOWLEDGEMENT patients in the study must be included in results re- The authors would like to thank the following collaborators for their par- porting, even those who are not evaluable or experi- ticipation in the REiNS functional outcomes working group: Dusica Ba- ence major protocol deviations. Patients should be bovic-Vuksanovic, MD, Mayo Clinic; Kathy Gardner, MD, University of Pittsburgh; James Tonsgard, MD, University of Chicago; Vanessa designated as either facial response, stable facial func- Merker, BS, Massachusetts General Hospital; Kent Robertson, MD, tion, progressive facial weakness, or not evaluable PhD, Riley Hospital for Children, Indianapolis; Elizabeth Schorry, MD, (e.g., early death, toxicity, assessment not performed). Cincinnati Children’s Hospital Medical Center; William Slattery III, In general, the denominator for calculation of the MD, House Clinic; and Bradley Welling, MD, PhD, Ohio State University. response rate should include all eligible patients. Con- clusions should not be based on selected “evaluable” STUDY FUNDING patients. For phase III trials, response evaluation may No targeted funding reported. be a primary or secondary endpoint. If response evaluation is a primary endpoint (i.e., the study includes DISCLOSURE only patients who have baseline facial weakness), the S. Plotkin has been reimbursed by the American Academy of Neurology discussion above should apply. If response evaluation and the Children’s Tumor Foundation for travel for educational activi- is a secondary endpoint (i.e., the study includes all ties. He has received research support from the Department of Defense (W81XWH-091-0182, NF050202, W81XWH-12-1-0155, PI), the patients regardless of facial function), the response Children’s Tumor Foundation (PI), and Johns Hopkins Medical Insti- rate may be reported using an “intention-to-treat” tutes (site PI). S. Ardern-Holmes served on a scientific advisory board for analysis (with all randomized patients in the denom- Novartis Pharmaceuticals Australia, received funding for a trip from No- inator) or using a predefined subset analysis (includ- vartis Pharmaceuticals Australia, and receives research support from The Children’s Tumor Foundation of Australia. F. Barker served as a scientific ing the subset of patients with facial weakness at reviewer for the Department of Defense CDMRP panels on neurofibro- baseline). The study protocol should specify how matosis and tuberous sclerosis. He serves as section editor for Neurosur- response results will be reported, including any gery and has received travel expenses for lectures and educational activities not funded by industry. J. Blakeley received travel support from the planned subset analyses. Children’s Tumor Foundation, the American Academy of Neurology, and the American Society of Clinical Oncology. She receives research Other outcomes for facial function: House-Brackmann support from GlaxoSmithKline, Sanofi-Aventis, Eli Lilly, the Cancer scale. As noted above, facial function in patients Therapy Evaluation Program, and the Children’sTumorFoundation. with VS is commonly monitored using the HB D. Evans has served on the scientific advisory boards of Breast Cancer scale.10 Given the widespread use of this scale and Campaign and the Genesis Breast Cancer Prevention Appeal. He is on 34 the editorial board of Familial Cancer. He received research support from its correlation with other scales of facial function, the Samantha Dickenson Brain Tumor Trust, Cancer Research-UK, the the committee recommends that the HB score be Children’s Tumor Foundation, the Association of International Cancer recorded as a secondary outcome for trials of NF2 Research, the Medical Research Council, the British Skin Foundation, patients with VS. CLAHRC for Greater Manchester, CMFT RfPB, BDRF, Genome Can- ada, Genesis Breast Cancer Prevention Appeal, and Children with Cancer UK. R. Ferner received funding for travel from the Children’sTumor CONCLUSION These recommendations by the REiNS Foundation and the European Neurofibromatosis Association. She re- Collaboration are intended to provide researchers with a ceives royalties from Springer for the book Neurofibromatoses in Clinical common set of endpoints for clinical trials for patients Practice. T. Hadlock reports no disclosures. C. Halpin received travel funding from CLAVE. He is an associate editor for the Journal of Speech, with NF. The use of shared endpoints will improve Language, and Hearing Research. He receives research support from NIH/ the quality of clinical trials and encourage pharmaceuti- NIDCD grants 1R21DC012407-0181 and 1U01DC010811-01A1, as cal companies to invest in drug development in this well as Department of Defense grant W81XWH-12-1-0155. Go to Neurology.org for full disclosures. patient population. The REiNS International Collabora- tion recognizes that no criteria are perfect and that alter- Received May 10, 2013. Accepted in final form September 5, 2013. native endpoints can be justified for these studies. In the future, the group intends to update these recommenda- REFERENCES tions as more information is published about clinically 1. Evans DG. Neurofibromatosis 2. In: Pagon RA, Bird TD, relevant endpoints. Dolan CR, editors. Seattle: University of Washington; 2011. 2. Neary WJ, Hillier VF, Flute T, Stephens D, Ramsden RT, AUTHOR CONTRIBUTIONS Evans DG. Use of a closed set questionnaire to measure SR Plotkin: drafting the manuscript, study concept, interpretation of primary and secondary effects of neurofibromatosis type 2. data. SL Ardern-Holmes: revising the manuscript for content, study con- J Laryngol Otol 2010;124:720–728. cept, interpretation of data. FG Barker: drafting the manuscript, study concept, interpretation of data. JO Blakeley: revising the manuscript 3. Neary WJ, Hillier VF, Flute T, Stephens SD, Ramsden RT, for content, study concept, interpretation of data. DG Evans: revising Evans DG. The relationship between patients’ perception of the manuscript for content, study concept, interpretation of data. RE the effects of neurofibromatosis type 2 and the domains of Ferner: revising the manuscript for content, study concept, interpretation the Short Form-36. Clin Otolaryngol 2010;35:291–299.

Neurology 81 (Suppl 1) November 19, 2013 S31 4. Hornigold R, Golding J, Leschziner G, et al. The NFTI- 21. De Cardenas M, Marrero V. Cuaderno de logoaudiome- QOL: a disease-specific quality of life questionnaire for tria. Madrid: Universidad Nacional de Educacion a Dis- neurofibromatosis 2. J Neurol Surg B Skull Base 2012; tancia; 1994. 73:104–111. 22. Plotkin SR, Stemmer-Rachamimov AO, Barker FG, 5. Masuda A, Fisher LM, Oppenheimer ML, Iqbal Z, et al. Hearing improvement after bevacizumab in pa- Slattery WH. Hearing changes after diagnosis in neurofi- tients with neurofibromatosis type 2. N Engl J Med bromatosis type 2. Otol Neurotol 2004;25:150–154. 2009;361:358–367. 6. Tysome JR, MacFarlane R, Durie-Gair J, et al. Surgical 23. Plotkin SR, Merker VL, Halpin C, et al. Bevacizumab for management of vestibular schwannomas and hearing reha- progressive vestibular schwannoma in neurofibromatosis bilitation in neurofibromatosis type 2. Otol Neurotol type 2: a retrospective review of 31 patients. Otol Neuro- 2012;33:466–472. tol 2012;33:1046–1052. 7. Friedman RA, Goddard JC, Wilkinson EP, et al. Hearing 24. Karajannis MA, Legault G, Hagiwara M, et al. Phase II preservation with the middle cranial fossa approach for neu- trial of lapatinib in adult and pediatric patients with neurofibromatosis type 2. Otol Neurotol 2011;32:1530–1537. rofibromatosis type 2 and progressive vestibular schwan- 8. Halpin C. Measuring audiometric outcomes. In: Shin J, nomas. Neuro Oncol 2012;14:1163–1170. Hartnick C, Randolph G, editors. Evidence Based Otolar- 25. Hirsh IJ, Davis H, Silverman SR, Reynolds EG, Eldert E, yngology. New York: Springer; 2008:227–238. Benson RW. Development of materials for speech audi- 9. Bess FH, Josey AF, Humes LE. Performance intensity ometry. J Speech Hear Disord 1952;17:321–337. functions in cochlear and eighth nerve disorders. Am J 26. Halpin C, Thornton AR. Q/MASS Volume 2: recording Otol 1979;1:27–31. of speech audiometry materials. Minneapolis: Massachu- 10. House JW, Brackmann DE. Facial nerve grading system. setts Eye and Ear Infirmary/Qualitone Inc; 1991. Otolaryngol Head Neck Surg 1985;93:146–147. 27. Plotkin SR, Merker VL, Muzikansky A, Barker FG II, 11. Vrabec JT, Backous DD, Djalilian HR, et al. Facial nerve Slattery W III. Natural history of vestibular schwannoma grading system 2.0. Otolaryngol Head Neck Surg 2009; growth and hearing decline in newly diagnosed neurofi- 140:445–450. bromatosis type 2 patients. Otol Neurotol 2013. In press. 12. Kang TS, Vrabec JT, Giddings N, Terris DJ. Facial nerve 28. Monsell EM. New and revised reporting guidelines from grading systems (1985-2002): beyond the House-Brack- the Committee on Hearing and Equilibrium. American mann scale. Otol Neurotol 2002;23:767–771. Academy of Otolaryngology-Head and Neck Surgery 13. American Academy of Otolaryngology-Head and Neck Foundation, Inc. Otolaryngol Head Neck Surg 1995; Surgery Foundation I. Committee on hearing and equilib- 113:176–178. rium guidelines for the evaluation of hearing preservation 29. Caye-Thomasen P, Dethloff T, Hansen S, Stangerup SE, in acoustic neuroma (vestibular schwannoma). Otolaryng- Thomsen J. Hearing in patients with intracanalicular ves- ol Head Neck Surg 1995;113:179–180. tibular schwannomas. Audiol Neurootol 2007;12:1–12. 14. Gardner G, Robertson JH. Hearing preservation in uni- 30. Mahmud MR, Khan AM, Nadol JB Jr. Histopathology of lateral acoustic neuroma surgery. Ann Otol Rhinol Lar- the inner ear in unoperated acoustic neuroma. Ann Otol yngol 1988;97:55–66. Rhinol Laryngol 2003;112:979–986. 15. Halpin C, Rauch SD. Using audiometric thresholds and 31. Vakharia KT, Henstrom D, Plotkin SR, Cheney M, word recognition in a treatment study. Otol Neurotol Hadlock TA. Facial reanimation of patients with neurofi- 2006;27:110–116. bromatosis type 2. Neurosurgery 2012;70:ons237–ons243. 16. Brackmann DE, Owens RM, Friedman RA, et al. Prog- 32. Hadlock TA, Malo JS, Cheney ML, Henstrom DK. nostic factors for hearing preservation in vestibular Free gracilis transfer for smile in children: the Massa- schwannoma surgery. Am J Otol 2000;21:417–424. chusetts eye and ear infirmary experience in excursion 17. Bray D, Henstrom DK, Cheney ML, Hadlock TA. Assess- and quality-of-life changes. Arch Facial Plast Surg 2011; ing outcomes in facial reanimation: evaluation and valida- 13:190–194. tion of the SMILE system for measuring lip excursion 33. Hadlock TA, Urban LS. Toward a universal, automated during smiling. Arch Facial Plast Surg 2010;12:352–354. facial measurement tool in facial reanimation. Arch Facial 18. Lee LN, Susarla SM, Hohman H, Henstrom DK, Plast Surg 2012;14:277–282. Cheney ML, Hadlock TA. A comparison of facial nerve 34. Berg T, Jonsson L, Engstrom M. Agreement between the grading systems. Ann Plast Surg 2013;70:313–316. Sunnybrook, House-Brackmann, and Yanagihara facial 19. Bess F, Humes L. Audiology: The Fundamentals, 4th ed. nerve grading systems in Bell’s palsy. Otol Neurotol Philadelphia: Lippincott Williams and Wilkins; 2008. 2004;25:1020–1026. 20. Halpin C. Audiologic evaluation and hearing ids. In: 35. Thornton AR, Raffin MJ. Speech-discrimination scores Lazar R, editor. Neurorehabilitation. New York: modeled as a binomial variable. J Speech Hear Res McGraw-Hill; 1998:649–676. 1978;21:507–518.

S32 Neurology 81 (Suppl 1) November 19, 2013