CCR PEDIATRIC ONCOLOGY SERIES CCR Pediatric Oncology Series PTEN, DICER1, FH, and Their Associated Tumor Susceptibility Syndromes: Clinical Features, Genetics, and Surveillance Recommendations in Childhood Kris Ann P. Schultz1, Surya P. Rednam2, Junne Kamihara3, Leslie Doros4, Maria Isabel Achatz5, Jonathan D. Wasserman6, Lisa R. Diller7, Laurence Brugieres 8, Harriet Druker9,10, Katherine A. Schneider11, Rose B. McGee12, and William D. Foulkes13 Abstract PTEN hamartoma tumor syndrome (PHTS), DICER1 syn- ovarian sex cord–stromal tumors, and multinodular goiter and drome, and hereditary leiomyomatosis and renal cell cancer thyroid carcinoma as well as brain tumors including pineoblas- (HLRCC) syndrome are pleiotropic tumor predisposition syn- toma and pituitary blastoma. Individuals with HLRCC may dromes that include benign and malignant neoplasms affecting develop multiple cutaneous and uterine leiomyomas, and they adults and children. PHTS includes several disorders with shared have an elevated risk of renal cell carcinoma. For each of these and distinct clinical features. These are associated with elevated syndromes, a summary of the key syndromic features is provided, lifetime risk of breast, thyroid, endometrial, colorectal, and renal the underlying genetic events are discussed, and specific screening cancers as well as melanoma. Thyroid cancer represents the is recommended. Clin Cancer Res; 23(12); e76–e82. Ó2017 AACR. predominant cancer risk under age 20 years. DICER1 syndrome See all articles in the online-only CCR Pediatric Oncology includes risk for pleuropulmonary blastoma, cystic nephroma, Series. Introduction PHTS PTEN hamartoma tumor syndrome (PHTS), DICER1 syn- PHTS (OMIM þ601728) encompasses several autosomal drome, and hereditary leiomyomatosis and renal cell cancer dominant disorders with both overlapping and distinctive syndrome are pleiotropic tumor predisposition syndromes that features (1). Syndromes definitively classified within the PHTS include benign and malignant neoplasms affecting children spectrum are Cowden syndrome (CS) and Bannayan–Riley– and adults. As the clinical findings and surveillance recommen- Ruvalcaba syndrome (BRRS). Some would also include PTEN- dations vary by syndrome, each syndrome is considered related Proteus-like syndromes (PS; refs. 1–3) under this rubric. separately here. Clinical features shared among the different PHTS conditions include macrocephaly (CS/BRRS), gastrointestinal polyposis (CS/BRRS), lipomas (CS/BRRS/PS), vascular malformations 1International Pleuropulmonary Blastoma Registry, Cancer and Blood Disorders, (BRRS/PS), and intellectual disability/autism spectrum disor- 2 Children's Hospitals and Clinics of Minnesota, Minneapolis, Minnesota. Depart- der (PHTS/CS/BRRS; ref. 4). In addition, there are significant ment of Pediatrics, Baylor College of Medicine, Texas Children's Cancer Center, lifetime risks for malignancy in affected individuals, including Texas Children's Hospital, Houston, Texas. 3Boston Children's Hospital, Dana- Farber Cancer Institute, Boston, Massachusetts. 4Cancer Genetics Clinic, Chil- breast, endometrial, and colorectal cancer, renal cell carcinoma, dren's National Medical Center, Washington, DC. 5Clinical Genetics Branch, and melanoma, with thyroid cancer representing the predom- National Cancer Institute, Bethesda, Maryland. 6Division of Endocrinology, The inant risk in childhood (5). An overall prevalence for PHTS has Hospital for Sick Children, Toronto, Ontario, Canada. 7Boston Children's Hospital, not been established, but the prevalence of CS has been 8 Dana-Farber Cancer Institute, Boston, Massachusetts. Child and Adolescent estimated to be at least one in 200,000 (6). 9 Cancer Department, Gustave Roussy Cancer Campus, Villejuif, France. Division Epithelial differentiated thyroid cancer (DTC) occurs in as of Hematology/Oncology and Department of Genetic Counselling, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. 10Department many as one third of patients with PHTS (5). It can be preceded of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada. 11Pedi- by multinodular goiter. Papillary pathology is more common atric Cancer Genetic Risk Program, Dana-Farber Cancer Institute, Boston, than follicular, although there is an excess of follicular carci- Massachusetts. 12Department of Oncology, Division of Cancer Predisposition, noma relative to the general population (7). The risk starts 13 St. Jude Children's Research Hospital, Memphis, Tennessee. Department of in childhood, with the earliest reported case occurring at 7 years Human Genetics and Research Institute, McGill University Health Centre, McGill of age (8). As many as 5% of individuals with PHTS under University, Montreal, Quebec, Canada. 20 years of age will develop DTC (5). Other PHTS-related Corresponding Author: William D. Foulkes, McGill University Health Centre, 1001 cancers have rarely been reported in children (5, 9). There Decarie Boulevard, Montreal, Quebec H4A 3J1, Canada. Phone: 514-412-4427; are no conclusively established genotype–cancer phenotype Fax: 514-412-4296; E-mail: [email protected] correlations (10). However, individuals with missense patho- doi: 10.1158/1078-0432.CCR-17-0629 genic variants in the PTEN gene may have a lower risk of thyroid Ó2017 American Association for Cancer Research. cancer than other mutation types (11). e76 Clin Cancer Res; 23(12) June 15, 2017 Downloaded from clincancerres.aacrjournals.org on September 27, 2021. © 2017 American Association for Cancer Research. Miscellaneous Pediatric Cancer Susceptibility Syndromes PHTS genetic summary ultrasound findings should prompt referral to a provider with PHTS has an autosomal dominant mode of inheritance and is expertise in pediatric thyroid disease. There is currently no evi- characterized by heterozygous germline pathogenic variants in the dence that the outcome following DTC is different in PHTS than PTEN gene located on chromosome 10 at position q23.31 (1). in the general population, but there are insufficient data to be The PI3K/AKT/mTOR pathway, which plays a central role in cell- certain. In addition, there is a high rate of benign nodules among cycle processes including cell proliferation, is negatively regulated carriers, and so there is an increased risk of false positive findings by the PTEN gene (12). In this role, the PTEN gene can be (e.g., benign nodules) that may lead to unnecessarily aggressive considered a tumor suppressor. The penetrance of pathogenic interventions such as thyroidectomy. As such, a balanced discus- variants is near complete, and almost all individuals possessing sion about both benefits and risks of thyroid cancer screening germline PTEN gene pathogenic variants develop at least one should occur between the medical team and the family. Thyroid feature of PHTS by young adult years (1). Specific PTEN gene ultrasound should be preferably coordinated by a pediatric sub- pathogenic variants do not predict particular PHTS disorders, but specialist with experience in managing patients with PHTS. If a some potential correlations between the site of the mutation and family or medical provider opts against thyroid ultrasounds, the PHTS phenotype have been noted (1). physical examination of the thyroid gland should be presented as a less sensitive alternative. Children should also have annual PHTS cancer screening/surveillance protocols and health supervision visits, including a comprehensive physical recommendations examination with physicians primarily responsible for their PHTS Current National Comprehensive Cancer Network (NCCN) care from diagnosis. Current NCCN guidelines also address guidelines recommend annual thyroid ultrasounds starting at the surveillance of adult cancer risks in individuals with PHTS (13). time of PHTS diagnosis (Evidence: Category 2A; ref. 13). We advocate for modifying this guideline. The youngest reported DICER1 Syndrome case of PHTS-related thyroid cancer occurred in a 7 year old (8). Given the indolent nature of papillary thyroid carcinoma, DICER1 syndrome is an autosomal dominant hereditary we recommend initiation of ultrasound surveillance of the thy- tumor predisposition syndrome caused by pathogenic variants à roid at age 7. If the baseline ultrasound is negative (i.e., no nodules in the DICER1 gene (OMIM 606241, #601200; ref. 14). with sonographic features suggestive of malignancy), ultrasound Pleuropulmonary blastoma (PPB), the most common lung tumor may be repeated every 2 years through childhood. Suspicious of infancy and early childhood (15), was the first tumor described Table 1. Key clinical phenotypes associated with germline DICER1 pathogenic variants Approximate ages of Malignant (M) Phenotype and relative frequency susceptibility range (peak) or benign (B) Deaths associated in DICER1-mutated cases Most frequent phenotypes PPB Type I (cystic) PPB 0–24 m (8 m) M y, if progresses to type II or III Type II (cystic/solid) PPB 12–60 m (31 m) M y, 40% Type III (solid) PPB 18–72 m (44 m) M y, 60% Type Ir (cystic) PPB Any age B or M None observed Multinodular goitera 5–40 y (10–20 y) B n Cystic nephroma 0–48 m (undetermined) B n (see anaplastic sarcoma of kidney below) Sertoli–Leydig cell tumor of ovary 2–45 y (10–25 y) M y, <5% of cases Moderate frequency phenotypes Cervix embryonal rhabdomyosarcoma 4–45 y (10–20 y) M None observed Rare frequency phenotypes DTC 5–40 y (10–20 y) M None observed Wilms tumor 3–13 y (undetermined) M None observed Juvenile hamartomatous intestinal