Bisphosphonates and evidence for association with esophageal and gastric cancer: a systematic review and meta-analysis

OBJECTIVES: Concerns have been raised about a possible link between bisphosphonate use, and in particular alendronate, and upper gastrointestinal (UGI) cancer. A number of epidemiological studies have been published with conflicting results. We conducted a systematic review and meta-analysis of observational studies, to determine the risk of esophageal and gastric cancer in users of bisphosphonates compared with non-users. DESIGN: We searched PubMed, MEDLINE, EMBASE, Web of Knowledge and Cochrane Database of Systematic Reviews for studies investigating bisphosphonates and esophageal or gastric cancer. We calculated pooled ORs and 95% CIs for the risk of esophageal or gastric cancer in bisphosphonate users compared with non-users. We performed a sensitivity analysis of alendronate as this was the most common single drug studied and is also the most widely used in clinical practice. RESULTS: 11 studies (from 10 papers) examining bisphosphonate exposure and UGI cancer (gastric and esophageal), met our inclusion criteria. All studies were retrospective, 6/11 (55%) case–control and 5/11(45%) cohort, and carried out using data from 5 longitudinal clinical databases. Combining 5 studies (1 from each database), we found no increased risk, OR 1.11 (95% CI 0.97 to 1.27) of esophageal cancer in bisphosphonate users compared with non-users and no increased risk of gastric cancer in bisphosphonate users, OR 0.96 (95% CI 0.82 to 1.12). CONCLUSION: This is the fourth and most detailed meta-analysis on this topic. We have not identified any compelling evidence for a significantly raised risk of esophageal cancer or gastric cancer in male and female patients prescribed bisphosphonates.