Quantitative assessment of the associations between CYP1A1 polymorphisms and gastric cancer risk

A great number of studies regarding the association between MspI and Ile462Val polymorphisms in the CYP1A1 gene and gastric cancer have been published. However, the results have been inconsistent. In this study, a meta-analysis was performed to investigate the associations. Published literature from PubMed, ISI Web of Science and other Chinese databases were searched for eligible publications. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using random or fixed effect model. Nine studies (860 cases/2183 controls) for CYP1A1 MspI polymorphism and nine studies (1161 cases/3273 controls) for CYP1A1 Ile462Val polymorphism were included in this meta-analysis. MspI polymorphism was not associated with gastric cancer risk (dominant model, OR = 0.95, 95%CI 0.80–1.14; recessive model, OR = 1.01, 95%CI 0.76–1.35; CC vs. TT, OR = 1.03, 95%CI 0.76–1.41; TC vs. TT, OR = 0.95, 95%CI 0.78–1.15). Similarly, there was no association between Ile462Val polymorphism and gastric cancer risk (dominant model, OR = 0.93, 95%CI 0.79–1.10; recessive model, OR = 1.34, 95%CI 0.90–2.00; GG vs. AA, OR = 1.27, 95%CI 0.84–1.90; AG vs. AA, OR = 0.87, 95%CI 0.71–1.07). In the subgroup analysis, no significant association was found in ever smokers, never smokers, Asians and Caucasians. This meta-analysis suggested that there were no associations between CYP1A1 polymorphisms and gastric cancer.