A meta-analysis on alcohol drinking and gastric cancer risk

Background: Whether an association between alcohol drinking and gastric cancer risk exists is an open question. In order to provide a definite quantification of the association between alcohol drinking and gastric cancer risk, we conducted a meta-analysis of available data. Patients and methods: We carried out a PubMed search of articles published up to June 2010 and identified 44 case-control and 15 cohort studies, including a total of 34 557 gastric cancer cases. We derived meta-analytic estimates using random-effects models, taking into account correlation between estimates. We carried out a dose-risk analysis using nonlinear random-effects meta-regression models. Results: Compared with nondrinkers, the pooled relative risk (RR) was 1.07 [95% confidence interval (CI) 1.01-1.13] for alcohol drinkers and 1.20 (95% CI 1.01-1.44) for heavy alcohol drinkers (≥4 drinks per day). The pooled estimates were apparently higher for gastric noncardia (RR for heavy drinkers = 1.17, 95% CI 0.78-1.75) than for gastric cardia (RR = 0.99, 95% CI 0.67-1.47) adenocarcinoma. The dose-risk model estimated a RR of 0.95 (95% CI 0.91-0.99) for 10 g/day and 1.14 (95% CI 1.08-1.21) for 50 g/day. Conclusions: This meta-analysis provides definite evidence of a lack of association between moderate alcohol drinking and gastric cancer risk. There was, however, a positive association with heavy alcohol drinking.