Association between tumor necrosis factor-alpha 857C/T polymorphism and gastric cancer: a meta-analysis

Tumor necrosis factor-alpha (TNF-alpha) is an inflammatory cytokine which may play an important role on the immune response may control the progression of gastric cancer. Previous studies on the association between TNF-alpha 857C/T polymorphism and gastric cancer risk reported conflicting results. We performed a meta-analysis to comprehensively assess the association between TNF-alpha 857C/T polymorphism and gastric cancer risk. Literature search was performed for all publications on the association between TNF-alpha 857C/T polymorphism and gastric cancer risk through March 6, 2013. The pooled odds ratios (ORs) with their 95 % confidence interval (95 %CIs) were calculated to assess the association between TNF-alpha 857C/T polymorphism and gastric cancer risk. Nine individual case-control studies with a total of 5,054 subjects (1,835 cases and 3,219 controls) were finally included into the meta-analysis. Meta-analysis of total nine studies showed that TNF-alpha 857C/T polymorphism was significantly associated with increased risk of gastric cancer under four genetic models (for T vs. C: OR = 1.19, 95 %CI 1.07-1.33, P = 0.002; for TT vs. CC: OR = 1.44, 95 %CI 1.03-2.02, P = 0.032; for CT vs. CC: OR = 1.19, 95 %CI 1.05-1.36, P = 0.008; and for TT/CT vs. CC: OR = 1.21, 95 %CI 1.07-1.38, P = 0.003). Subgroup analysis by ethnicity further showed that there was a significant association between TNF-alpha 857C/T polymorphism and increased risk of gastric cancer in Asians but not in Caucasians. The meta-analysis suggests that TNF-alpha 857C/T polymorphism is significantly associated with increased risk of gastric cancer, especially in Asians.