GSTT 1 and gastric cancer susceptibility in the Chinese population : an updated meta-analysis and review

Aim: To assess the effects of GSTT1 null genotype on the risk of gastric cancer (GC), an updated metaanalysis was performed in the Chinese population. Methods: Related studies were identified from PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure (CNKI), and Chinese Biology Medicine (CBM) to up 5th March 2015. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of the associations. Results: A total of 19 case-control studies including 2861 GC cases and 5064 controls were involved in this meta-analysis. Overall, significantly increased GC risk was associated with the null GSTT1 with OR of 1.20 (95% CI: 1.04-1.38) in the Chinese population. In subgroup analyses stratified by geographic area and source of controls, the significant results were found in South China and population-based studies. We also undertook gene-gene interaction analysis between GSTT1 and GSTM1 genes for GC risk, and the results indicated that the dual null genotypes of GSTT1 and GSTM1 might elevate the risk of GC (OR = 2.02, 95% CI: 1.63-12.51). Conclusion: This meta-analysis suggests that GSTT1 null genotype is associated with elevated GC risk in Chinese, but these associations vary in different geographic location.