Tumor necrosis factor-α 238 G/A polymorphism and gastric cancer risk: a meta-analysis

Though many studies were performed to assess the association between tumor necrosis factor-alpha (TNF-alpha) 238 G/A polymorphism and gastric cancer risk, there were no conclusive findings. A meta-analysis of previous published studies was performed to get a comprehensive assessment of the association between TNF-alpha 238 G/A polymorphisms and gastric cancer. The pooled odds ratios (ORs) and 95 % confidence intervals (95 % CIs) were calculated to assess the association. Fifteen studies with a total of 7,795 participants were finally included into this meta-analysis. Overall, there was an obvious association between TNF-alpha 238 G/A polymorphism and increased risk of gastric cancer (A vs. G: OR = 1.32, 95 % CI 1.02-1.72, P = 0.036; GA vs. GG: OR = 1.32, 95 % CI 1.01-1.72, P = 0.042; and AA/GA vs. GG: OR = 1.34, 95 % CI 1.02-1.76, P = 0.036). Subgroup analysis by ethnicity showed the statistically significant association between TNF-alpha 238 G/A polymorphism and gastric cancer was limited to Asian populations (A vs. G: OR = 1.59, 95 % CI 1.29-1.97, P < 0.001; GA vs. GG: OR = 1.63, 95 % CI 1.29-2.04, P < 0.001; and AA/GA vs. GG: OR = 1.64, 95 %CI 1.31-2.05, P < 0.001), and there was no obvious association in Caucasians. In conclusion, TNF-alpha 238 G/A polymorphism is significantly associated with increased risk of gastric cancer, especially in Asians.