Reduced risk of colorectal cancer with use of oral bisphosphonates: A systematic review and meta-analysis

Purpose The association between oral bisphosphonate (BP) intake and colorectal cancer (CRC) risk has been investigated in several recent studies with conflicting results. We summarized the evidence from the published studies in a categorical, dose-response meta-analysis. Methods Relevant studies were identified by a search of MEDLINE and EMBASE databases through January 15, 2012. We included studies that reported effect size estimates with 95% CIs for the association between exposure to oral BPs and risk of CRC. Results Three case-control studies with a total of 16,998 CRC cases and 108,197 controls and one cohort study with 94,405 individuals exposed to BPs and 283,181 unexposed to BPs were included in meta-analysis. The random effect model meta-analysis suggested reduced risk of CRC with exposure to oral BPs with pooled odds ratio (OR) of 0.87 (95% CI, 0.78 to 0.97). Significant inverse relationship was noted for 10 or more prescriptions categories, with pooled ORs of 0.71 (95% CI, 0.58 to 0.87). Similarly, the analysis for 1 to 3 years of use and more than 3 years of use of BPs suggested a significant inverse relationship, with pooled ORs of 0.76 (95% CI, 0.68 to 0.85) and 0.78 (95% CI, 0.61 to 0.99), respectively. Conclusion This meta-analysis suggests that the use of oral BPs at a dose of 10 or more prescriptions or 1 or more years of duration is associated with reduced risk of CRC. Further randomized controlled trials are needed to prove this association.