Association of glutathione S-transferase M1, T1, and P1 polymorphisms with renal cell carcinoma: evidence from 11 studies

The glutathione S-transferases (GSTs) are a gene superfamily of phase II metabolic enzymes that has attracted a considerable attention as a candidate gene for renal cell carcinoma (RCC) based on its enzyme function as a key factor in biotransformation pathways. In the past decade, a number of case–control studies were conducted to investigate the association of GST genetic polymorphisms and RCC risk. However, studies on the association between GST (GSTM1, GSTT1, and GSTP1) polymorphisms and RCC remain to be conflicting. To derive a more precise estimation of the relationship, a meta-analysis of 2,189 cases and 3,817 controls from 11 case–control studies was performed. Overall, the summarized odds ratio for RCC of the GSTM1 null and GSTT1 null polymorphisms was 1.02 (95 % confidence interval (CI) 0.91–1.15, P = 0.70) and 1.28 (95 % CI 0.96–1.72, P = 0.09), respectively. No significant results were observed in heterozygous and homozygous genotypes when compared with wild-type genotype for GSTP1 I105V polymorphism. However, the GSTM1–GSTT1 interaction analysis showed that the dual null genotype of GSTM1/GSTT1 was significantly associated with an increased RCC risk (odds ratio (OR) = 1.42, 95 % CI 1.14–1.76, P = 0.001). In the stratified analyses by ethnicity, significant gene–disease association was obtained among Asians for GSTT1 and GSTP1 polymorphisms. In our meta-analysis, the associations between variations of GSTs and RCC may vary in different ethnic populations, and the interaction between unfavorable GST genotypes may exist.