Association between alcohol consumption and the risk of gastric cancer: a meta-analysis of prospective cohort studies.

Alcohol consumption is inconsistently associated with the risk of gastric cancer morbidity and mortality. The aim of this study was to systematically evaluate the association between alcohol consumption on gastric cancer risk. The PubMed, Embase, and Cochrane Library databases were searched from inception through April 2017. Prospective cohort studies evaluating the association between alcohol consumption and risk of gastric cancer which report its effect estimates with 95% confidence intervals (CIs) were included. The results summary was performed using the random-effect model. Twenty-two cohort studies involving 22,545 cases of gastric cancer and 5,820,431 participants were identified and included in our data analysis. Overall, drinking had little or no effect on gastric cancer as compared with non-drinkers. Furthermore, light and moderate alcohol consumption had no significant effect on gastric cancer risk when compared with non-drinkers. However, heavy alcohol consumption was associated with a greater risk of gastric cancer when compared with non-drinkers. The findings of the subgroup analyses indicated that light alcohol consumption was associated with a lower risk of gastric cancer in women, while heavy alcohol consumption was associated with an increased risk of gastric cancer regardless of country, gender, whether the study reported gastric cancer incidence, or whether the study adjusted for body mass index, educational attainment, or physical activity. The findings of this study suggest that light alcohol consumption might play a protective effect on gastric cancer in women, while heavy alcohol consumption is associated with a significantly increased risk of gastric cancer in all subgroups.