Risk factors for bone metastasis in patients with primary lung cancer: study protocol for a systematic review

INTRODUCTION: Bone metastasis (BM) in patients with primary lung cancer poses a serious health problem. Numerous risk factors have been hypothesised to predict BM in these patients, but research studies are of mutable quality, and may not be of value in clinical evaluation. METHODS AND ANALYSIS: We will search a number of electronic databases including PubMed, MEDLINE, Web of Science, EMBASE, the Cochrane Library (Cochrane Database of Systematic Reviews) and the Cochrane Central Register of Controlled Trials (CENTRAL). We will carry out a secondary search for articles from references of included articles (from January 1990 to June 2014). Primary and secondary outcomes will be BM and skeletal-related events information. We will summarise the effect estimates of risk factors and use random-effect models to pool the estimates, if the outcomes and characteristics in studies are comparable. The quality of the study will be assessed using the Newcastle–Ottawa Scale and the Cochrane Collaboration tool. TRIAL REGISTRATION NUMBER: CRD42013003744.