Null genotype of glutathione S-transferase T1 contributes to increased risk of gastric cancer in Asian population

Numerous studies were published to investigate the relationship between the glutathione S-transferase T1 (GSTT1) null genotype and risk of gastric cancer in Asians, but the conclusions from those studies were conflicting. To get a more precise estimation on the possible association, we performed a meta-analysis of published data. A comprehensive literature was conducted and 27 case-control studies with 14,905 individuals were finally included, involving a total of 6,270 cases and 8,635 controls. The strength of the association between GSTT1 polymorphism and gastric cancer risk was estimated by calculating the pooled odds ratio with its 95 % confidence interval (95 % CI). A meta-analysis of total 27 studies showed that GSTT1 null genotype was obviously associated with increased risk of gastric cancer in Asians (random effect odds ratio (OR) = 1.29, 95 % CI 1.16-1.44, P (OR) < 0.001). A subgroup analysis of 14 studies with large sample size also showed an obvious association between GSTT1 null genotype and increased risk of gastric cancer in Asians (fixed effect OR = 1.14, 95 % CI 1.06-1.23, P (OR) = 0.001). In conclusion, the meta-analysis suggests that null genotype of GSTT1 contributes to increased risk of gastric cancer in Asian population.