Association between TNF-α 238 G/A polymorphism and gastric carcinoma risk: a systematic review and a meta-analysis

Although numerous studies have been conducted to estimate the correlation between tumor necrosis factor-alpha (TNF-alpha) 238 G/A polymorphisms and gastric carcinoma risk, the results were conflicting. Therefore, we performed a quantitative updated meta-analysis on published studies to address this issue. The association between TNF-alpha 238 G/A polymorphism and gastric carcinoma risk was evaluated by odds ratios (ORs) with 95% confidence intervals (95% CIs) from each study. A total of 25 studies comprising 5008 gastric carcinoma cases and 9828 control subjects were included in this meta-analysis. The overall data demonstrated that there was a statistically significant association of TNF-alpha 238 G/A polymorphism with the increased gastric cancer risk (AA/GA vs. GG: OR= 1.21, 95% CI 1.10-1.34, P= 0.0002; GA vs. GG: OR= 1.15, 95% CI 1.04-1.28, P= 0.008; AA vs. GG: OR= 1.58, 95% CI 1.19-2.09, P= 0.002; A vs. G: OR= 1.23, 95% CI 1.12-1.34, P< 0.0001). Stratified analysis suggested that TNF-alpha 238 G/A polymorphism was significantly associated with the susceptibility of gastric carcinoma in the Asian populations in the dominant model (AA/GA vs. GG) (OR= 1.22, 95% CI 1.01-1.46, P= 0.03) and the allele model (A vs. G) (OR= 1.21, 95% CI 1.03-1.43, P= 0.02), and an statistically significant correlation was found in Caucasians in all models (A vs. G: OR= 1.18, 95% CI 1.05-1.33, P= 0.005; GA vs. GG: OR= 1.16, 95% CI 1.01-1.33, P= 0.04; AA vs. GG: OR= 1.42, 95% CI 0.94-2.14, P= 0.09; and AA/GA vs. GG: OR= 1.20, 95% CI 1.05-1.37, P= 0.009). Collectively, TNF-alpha 238 G/A polymorphism is statistically associated with the increased risk of gastric carcinoma, especially in Caucasians.