Subgroup analysis showed a significant relationship between GSTT1 null genotype and gastric cancer in East-Asians, as well as in subgroup analysis of hospital-based design.
We examined the association between single nucleotide polymorphisms (SNPs) of CYP1A1 (rs4646421, rs4646422 and rs1048943), GSTM1 and GSTT1 and gastric cancer risk in Japan.
Further well-designed studies are required to confirm the association between GSTT1 polymorphisms and gastric cancer risk in relation to various clinicopathological factors in different ethnic groups, especially Caucasians.
In conclusion, this meta-analysis suggests that GSTT1 null polymorphism is associated with elevated GC risk, but these associations vary in different ethnic populations.
This investigation was performed to assess the association of the GSTT1 null/presence gene polymorphism with the risk of gastric carcinoma via a meta-analysis to increase sample size and statistical significance.
After adjusting for other confounding variables, GSTT1 null genotype was also significantly associated with increased risk of gastric cancer (Random-effect OR = 1.43, 95%CI 1.20-1.71, P OR <0.001, I(2) = 48.1%).
The cumulative meta-analysis showed a trend of a more obvious association between GSTT1 null genotype and risk of gastric cancer in Chinese population as information accumulated gradually.
Our study provided evidence that genetic deletion of GSTM1 and GSTT1 may contribute to increased susceptibility to gastric cancer in our Chinese population, while the GSTP1a/b polymorphism may not.
In subgroup analysis stratified on the basis of ethnic group, we also observed positive association between GSTT1 polymorphism and gastric cancer risk among Caucasians (non-Europeans + non-Americans), but not among East Asians.
However, when data was analyzed in different geographic regions the GSTT1 null genotype was found to be a significant risk factor for oral (OR = 2.58, 95% CI 1.01-6.61, p = 0.05) as well as gastric cancer (OR = 3.08, 95% CI 1.32-7.19, p = 0.009) in samples obtained from the Assam region of NE India.
In order to study whether GSTO2, GSTM1, and GSTT1 polymorphisms are associated with increased gastric cancer risk in Iranian patients, the present case-control study was done.
The gene-gene interaction analyses demonstrated that individuals with combined GSTT1 null and NAT2 slow acetylators had an additional increased risk of gastric cancer, with an OR of 3.00 (95%CI: 1.52-5.93) and an AP of 52%.