Role of Glutathione-S-Transferases in Gallbladder Cancer and Cholelithiasis Susceptibility and Meta-Analysis

Glutathione-S-transferase T1 (GSTT1) and glutathione-S-transferase M1 (GSTM1) genes are associated with increase susceptibility to developing different types of cancers. The aim of present study was to investigate the role of genetic variants of GSTM1 and GSTT1 in gallbladder cancer (GBC) and cholelithiasis in Kashmir valley. Genotyping was done by multiplex polymerase chain reaction in 100 GBC, 100 cholelithiasis, and 150 controls adjusted by age and sex. We also performed a meta-analysis of published studies on GSTM1 and GSTT1 to evaluate the association between the GSTM1 and GSTT1 polymorphisms and GBC. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using random- or fixed-effects model. In the present study, no association was observed between GSTM1 null and GSTT1 null genotypes and GBC and cholelithiasis. Meta-analysis results showed that GSTM1 null genotype was associated with GBC risk (P = 0.042). Subgroup analysis by ethnicity showed that GSTM1 null (P = 0.024) and GSTT1 null genotype (P = 0.037) were significantly associated with risk of GBC in Asians. This is the first study to investigate the role of genetic variants of GSTM1 and GSTT1 in GBC in Kashmir valley and cholelithiasis in the world.