An updated meta-analysis of transforming growth factor-β1 gene: three polymorphisms with gastric cancer

To derive a more precise estimation of the relationship between TGF-β1 polymorphisms and gastric cancer (GC) risk, we conducted a meta-analysis of all available case-control studies relating the C-509 T, T869C, and G 915C polymorphisms of the TGF-β1 gene to the risk of developing GC. The effect summary odds ratio (OR) and 95% confidence intervals (CIs) were obtained. Funnel plots and Egger's test were used to estimate publication bias. Finally, 11 studies were included in the final meta-analysis. With respect to C-509 T polymorphism, it was found that significantly increased GC risk was associated with the TT genotype in the recessive genetic model in overall analysis (TT vs. CC + CT: OR = 1.23, 95% CI 1.09-1.38, P(heterogeneity) = 0.13) and in Asian population (TT vs. CC + CT: OR = 1.24, 95% CI 1.10-1.39, P(heterogeneity) = 0.18). With respect to T869C and G915C polymorphisms, no significant association with GC risk was demonstrated in overall analysis and subgroup analyses according to ethnicity for all genetic models. This meta-analysis suggested that the T allele of TGF-β1 509C/T polymorphism is probably the susceptibility factor for GC.