Exposure to bisphosphonates and risk of colorectal cancer.

Animal and in vitro studies suggest that the use of bisphosphonates (BPs) may be associated with reduced risk for colorectal cancer (CRC). However, results from these studies have been inconsistent. The aim of our study was to review and summarize the evidence provided by longitudinal studies on the association between BP use and CRC risk A comprehensive literature search for articles published up to October 2012 was performed. Prior to performing a meta-analysis, the studies were evaluated for publication bias and heterogeneity. Relative risks (RRs) or odds ratios were calculated. Six reports (four case-control studies and two cohort studies) published between 2010 and 2012 were identified. There was evidence of an association between any use of BPs and CRC risk using a fixed-effects model (RR = 0.80, 95% confidence interval = 0.74, 0.85) and a random-effects model (RR = 0.80, 95% confidence interval = 0.71, 0.90). However, we did not observe any evidence of a trend with increasing duration of use. Our findings indicate that there is evidence of an association between any use of BP and reduced CRC risk. However, this subject deserves further investigation.