Association of Risk of Gastric Cancer and Consumption of Tobacco, Alcohol and Tea in the Chinese Population

This study aimed at summarizing epidemiological research findings on associations between tobacco, alcoholand tea consumption and risk of gastric cancer (GC) in the Chinese population. The review searched PubMed,Embase, China National Knowledge Infrastructure (CNKI) and China Biology Medicine (CBM) databases andreference lists of review papers for all studies published in English or Chinese languages. Information extracted,via two independent researchers, from retrieved articles included first author, year of publication, study design,sample size, source of controls and adjusted odds ratio (OR) or relative risk (RR) with the corresponding 95%confidence intervals (CIs) for each category. Statistical analyses used software STATA version 12.0. The systematicsearch found 89 articles containing 25,821 GC cases and 135,298 non-cases. The overall random effects in termsof pooled OR and 95%CI for tobacco, alcohol and tea consumption were 1.62 (95%CI: 1.50-1.74), 1.57 (95%CI:1.41-1.76) and 0.67 (95%CI: 0.59-0.76) respectively; while the heterogeneity among included studies rangedfrom 80.1% to 87.5%. The majority of subgroup analyses revealed consistent results with the overall analyses.All three behavioral factors showed statistically significant dose-dependent effects on GC (P<0.05). The studyrevealed that tobacco smoking and alcohol drinking were associated with over 1/2 added risk of GC, while teadrinking conferred about 1/3 lower risk of GC in the Chinese population. However, these results should beinterpreted with caution given the fact that most of the included studies were based on a retrospective designand heterogeneity among studies was relatively high.