EDUCATION CLINICAL REVIEW Cancer induced bone pain • Link to this article online 1 2 1 for CPD/CME credits Christopher M Kane, Peter Hoskin, Michael I Bennett 1 Bone pain is the most common type of pain from cancer Academic Unit of Palliative Care, SOURCES AND SELECTION CRITERIA Leeds Institute of Health Sciences, and is present in around one third of patients with bone School of Medicine, University of metastases.1 2 Based on postmortem studies of patients We searched Medline, Clinical Evidence, and the Cochrane Leeds, Leeds, UK Library using the terms “bone metastases”, “pain”, and 2 with advanced cancer and clinical knowledge of how Mount Vernon Cancer Centre, “bone pain” and then combined these with the specific often bone metastases result in pain, the incidence of Northwood, University College treatment terms individually. Where possible we have used London, London, UK cancer induced bone pain is estimated at 30 000 patients systematic reviews but not referenced trials included in Correspondence to: C M Kane in the United Kingdom each year.3 w1 Currently, improve- [email protected] these reviews. We limited our search from 1990 to December ments in cancer treatments mean that many patients Cite this as: BMJ 2015;350:h315 2014. We also searched the National Institute for Health and doi: 10.1136/bmj.h315 are living with metastatic cancer for several years. The Care Excellence and the Scottish Intercollegiate Guidelines prevalence of cancer induced bone pain is therefore likely Network. In calculating the numbers needed to treat, we to be much greater than the annual incidence.w1 Cancer have assumed a conservative placebo response of 25%. induced bone pain is considered one of the most difficult pain conditions to treat because of its frequent associa- well as myeloma.3 The most common sites of metastases tion with weight bearing and movement. Not surprisingly, are vertebrae, pelvis, long bones, and ribs.3 At postmor- it has a major impact on patients’ daily functioning and tem examination, up to 70% of patients who died of can- mood and can result in admission to hospital.w2 w3 cer will have bone metastases.3 Bone metastases can be Given the prevalence of cancer induced bone pain, it is found in a wide range of places (figure). However, not all likely that clinicians in primary or secondary care will be patients with bone metastases get pain; bone pain was thebmj.com confronted by patients in pain crises. Recognising and ini- identified in only a third of patients with bone metasta- Previous articles in this tiating management of this specific pain state, as well as ses in one large prospective study.1 It is not yet clear why series an awareness of the specialist treatments, is important for some bone metastases cause pain and others do not. • Managing patients all clinicians. with multimorbidity in What are the clinical features of cancer induced bone pain? primary care What is cancer induced bone pain? In a cross sectional survey in 2011 patients described (BMJ 2015;350:h176) Cancer induced bone pain is a specific pain state with their cancer induced bone pain as annoying, gnawing, w4 • The prevention and overlapping but distinct features of both inflammatory and aching, and nagging. The pain is commonly a mixture 4 management of rabies neuropathic pain. The most important changes are in bone of steady background pain, as well as pain that is exac- homeostasis, with corresponding events in the peripheral erbated by weight bearing or movement, called incident (BMJ 2015;350:g7827) 5 4 • Heparin induced and central nervous system. When combined with the or episodic pain. In a recent well conducted European- destruction of nerve endings through cancer invasion, the wide observational study of 1000 patients with cancer, thrombocytopenia resulting pain is a mixture of ongoing inflammatory and 85.5% reported some form of incident pain episodes.6 (BMJ 2014;349:g7566) neuropathic processes, which lead to a hyperexcitability The presence of movement related pain has most impact • The management of state within the spinal cord. Patients experience this as on function and daily activity.w4 chronic breathlessness in constant pain, with high sensitivity to movement.4 Cancer induced bone pain is most commonly expe- patients with advanced rienced in the lower back, pelvis, long bones, and ribs. and terminal illness Who gets cancer induced bone pain? This can be the presenting feature of the cancer or high- (BMJ 2015;350:g7617) Cancer induced bone pain can occur anywhere that light a recurrence in those previously treated. Therefore • Ebola virus disease cancer has metastasised to bone. Cancers most often in patients with or without active cancer, persistent pain (BMJ 2014;349:g7348) involved are those of the prostate, breast, and lung, as in these areas should alert clinicians to the possibility of bone metastases. Findings on examination are often THE BOTTOM LINE non-specific with only some tenderness over the site of metastasis or pain specifically related to movement. • Cancer induced bone pain is a common problem, which can be extremely debilitating to patients with an already limited life expectancy A bony metastasis can weaken bone sufficiently such that an innocuous movement, bump, or fall may result in • When treating cancer induced bone pain, maintenance of function should be a pathological fracture. Vertebral pain should always alert given high priority alongside pain relief clinicians to the risk of spinal cord compression, espe- • Early recognition, intervention with functional aids, and behaviour cially in the presence of sensory disturbance, g eneralised modification, combined with initial titration with analgesia (commonly, leg weakness, or changes in bladder or bowel function. strong opioids) are important first steps for non-specialists Even without “red flag” signs, a full neurological examina- • The evidence for early referral for radiotherapy is strong, although tion should be done in these patients, with a low threshold bisphosphonates will have an important role for some patients for a spinal magnetic resonance scan.7 Even if suspicion • Specialist support will be required if pain persists despite initial treatment is low, advice should be sought from the patient’s oncolo- with behaviour modification, commencement of a non-steroidal gist; retrospective cohort studies have shown that being anti-inflammatory drug, and initial titration of a strong opioid able to walk at the time of diagnosis of spinal cord com- pression is correlated with overall survival and the a bility the bmj | 31 January 2015 27 EDUCATION CLINICAL REVIEW to walk after treatment. Early diagnosis and treatment Behaviour A PATIENT’S PERSPECTIVE of impending spinal cord compression can drastically modifications . can 8 9 I was diagnosed with cancer on my wedding anniversary make important improve quality of life for patients. a year ago. I developed back pain, which felt exactly the contributions to Table 1 outlines the advantages and disadvantages of same as sciatica; however, it wasn’t getting any better. One the various investigations for suspected cancer induced Saturday it became so unbearable that I went to A and E and the maintenance of bone pain. Generalists may consider plain film radiog- they diagnosed a water infection and sent me home with function and quality raphy or computed tomography as initial investigations; antibiotics. I saw my general practitioner and he sent me of life other investigations are usually undertaken by specialists. back to A and E where they did a scan and told me my kidney looked slightly inflamed. They said it would settle down in a few days with antibiotics. They called me back a few days How is cancer induced bone pain initially managed? later to tell me they’d found cancer in the bones in my back The first steps in management are simple measures that and my pelvis on the scan I’d had. can be initiated in non-specialist care, while referral for Since then the pain has been bad but it’s the things that it specialist treatments such as radiotherapy or bisphos- stops me from doing that I get upset about. I can’t swim or phonates is awaited. In the following section we describe walk anymore and it really wears you down. It’s affected my the evidence for each treatment that is commonly used for marriage so we now sleep in separate beds. cancer induced bone pain. Consider specialist referral in I’ve really appreciated the doctors’ help but they don’t understand that I don’t just want to lie in bed all day, any patient where pain persists despite these initial steps, because the tablets have made me sleepy. I want to be able those with rapidly increasing pain despite treatment or to do things and this is so important to me. I’d really like evidence of toxicity from opioids, and where pathological doctors to think about trying to make sure I’m able to do fracture or spinal cord compression are suspected. things still rather than just giving me tablets. Non-drug interventions counter analgesics helpful, several systematic reviews Important aspects of managing cancer induced bone pain that have examined the effectiveness of paracetamol for are to support patient self management and encourage cancer pain showed that although it was well tolerated the use of non-drug measures. An observational study there was no significant benefit particularly when added of 1000 European patients with cancer showed that to strong opioids.13 14 Non-steroidal anti-inflammatory in those who had pain on movement, many of whom drugs are often perceived to be more efficacious in cancer had bone metastasis, 43% found consistent pain relief induced bone pain than in other pain states, and this is with non-drug measures, often reported as either rest a reasonable assumption given the major inflammatory or sleep.6 Discussing behaviour modifications, such as component.