The tumor necrosis factor-α-238 polymorphism and digestive system cancer risk: a meta-analysis

Many studies have reported the association between tumor necrosis factor-α (TNF-α)-238 polymorphism and digestive system cancer susceptibility, but the results were inconclusive. We performed a meta-analysis to derive a more precise estimation of the relationship between TNF-α-238 G/A polymorphism and digestive system cancer risk. Pooled analysis for the TNF-α-238 G/A polymorphism contained 26 studies with a total of 4849 cases and 8567 controls. The meta-analysis observed a significant association between TNF-α-238 G/A polymorphism and digestive system cancer risk in the overall population (GA vs GG: OR 1.19, 95 % CI 1.00–1.40, P _{heterpgeneity} = 0.016; A vs G: OR 1.19, 95 % CI 1.03–1.39, P _{heterpgeneity} = 0.015; dominant model: OR 1.20, 95 % CI 1.02–1.41, P _{heterpgeneity} = 0.012). In the analysis of the ethnic subgroups, however, similar results were observed only in the Asian population, but not in the Caucasian population. Therefore, this meta-analysis suggests that TNF-α-238 G/A polymorphism is associated with a significantly increased risk of digestive system cancer. Further large and well-designed studies are needed to confirm these findings.