Bisphosphonates use and risk of gastric cancer: an updated meta-analysis of cohort and case-control studies

BACKGROUND: Studies evaluating the association between bisphosphonates exposure and gastric cancer (GC) risk have reached inconsistent conclusions. The purpose of this updated meta-analysis was to assess whether bisphosphonates exposure were associated with an increased risk of GC. EVIDENCE ACQUISITION: We searched PubMed and Embase database and reviewed reference lists of retrieved articles to identify potential studies. Study selection and data abstraction were performed by two independent observers. We calculated pooled odds ratios and 95% CIs using the random effects models. EVIDENCE SYNTHESIS: The pooled relative risk showed no significant relationship between bisphosphonates exposure and GC risk (adjusted OR, 0.996, 95% CI, 0.860-1.152). The results were stable across stratified analysis on study design, sex, and duration of follow-up and geographic locations. We also investigated whether different types of bisphosphonates affected the pooled RR. Neither use of bisphosphonates, alendronate, nor etidronate was associated with GC risk. CONCLUSIONS: Our meta-analysis found no overall association between GC risk and bisphosphonates use. Further studies with large sample size and more covariate adjustments are needed.