Genetic polymorphisms of glutathione S-transferase (GSTM1, GSTT1 and GSTP1) with esophageal cancer risk: a meta-analysis

Glutathione S-transferases (GSTs) are important phase II enzymes and play a crucial role in the elimination of electrophilic carcinogens. Numerous studies have investigated the association between GSTs gene variations with esophageal carcinoma risk, but a final conclusion has not been made. Then we searched PubMed, Web of Knowledge and China National Knowledge Infrastructure (CNKI) for relevant articles until June, 2015. We totally extracted and analyzed the pooled data form 43 published articles about GSTM1 null genotype, GSTT1 null genotype and GSTP1 Ile105Val polymorphism (rs1695) with esophageal carcinoma risk. GSTM1 null genotype and GSTT1 null genotype could significantly increase esophageal cancer risk (OR=1.27, 95% CI=1.11-1.44; OR=1.12, 95% CI=1.05-1.39 respectively). The subgroup analysis showed that the two mutations most likely contribute to esophageal squamous cell carcinoma susceptibility. And Asians carrying the homozygous null genotype were at higher esophageal cancer risk than Caucasians. While GSTP1 Ile105Val variants showed no significant effect to esophageal cancer risk. This meta-analysis provides evidence to support that GSTM1 and GSTT1 null genotypes could increase esophageal cancer risk, which would benefit the diagnosis and prevention of esophageal cancer.