ABSTRACT
To conduct a meta-analysis of observational studies to explore the relationships between cholecystectomy and the risk of esophageal and gastric cancer [GC]. The study design was retrospective, and carried out in the First People's Hospital of Nantong, Jiangsu, China from January 2012 to April 2012. Studies were identified by a literature search of MEDLINE and EMBASE through March 31, 2012, and by manually searching the reference lists of pertinent articles. The summary relative risks [SRRs] with their 95% confidence intervals [CIs] were calculated with a random-effects model. A total of 12 estimates from 6 independent studies [including 1,622 esophageal cancer [EC] cases and 2,314 GC cases] were included in this meta-analysis. We found that cholecystectomy was not associated with risk of EC and GC [EC: SRRs - 1.03; 95% CI: 0.94-1.13; heterogeneity: p=0.496; I2=0; n=4 studies; [GC: SRRs - 1.03; 95% CI: 0.93-1.13; heterogeneity: p=0.652; I2=0; n=5 studies]]. Sub-grouped analyses revealed that these null associations were independent of geographic location and study design. Based on 2 studies, we found patients undergoing cholecystectomy at least 10 years before had an elevated risk of esophageal adenocarcinoma [EAC]. The results of this meta-analysis suggest that cholecystectomy does not increase the risk of esophageal squamous cell carcinoma and GC development, but may increase EAC risk. More epidemiological research of a prospective design is needed to further clarify these associations in the future