Analyses of the GSTM1 polymorphisms demonstrated that there was a significantly increased EC risk in GSTM1 null genotype carriers (OR = 1.319, 95% CI = 1.125-1.546, p for heterogeneity <0.001).
In this study, we assessed the association of functional polymorphisms in GSTM1 and GSTT1 with esophageal cancer in Kashmir, India, an area with a high incidence of esophageal squamous cell carcinoma (ESCC).
Homozygous deletions of GSTM1 and GSTT1 have been suggested as risk factors for some cancers, including colorectal, pancreatic, and esophageal cancers.
A significant association of GSTM1 null genotype with esophageal cancer was observed in a younger age group in Assam (OR-2.7, 95 % CI, 1.48-5.01), and in Delhi population association was observed in smokers with GSTT1 null genotype (OR-2.5, 95 % CI, 1.04-6.07), and alcoholics having GSTM1 null genotype (OR-2.6, 95 % CI, 0.99-6.77).
Genetic polymorphisms of GSTM1, GSTT1 and GSTP1 in association with some environmental factors and their impact on esophageal cancer susceptibility were assessed in the Iranian population.
A case-control study was performed in 135 EC patients and 195 healthy controls to analyze association of polymorphisms in glutathione S-transferase (GST) mu (GSTM1), GST theta (GSTT1), GST pi (GSTP1), GSTM3, Cytochrome P450 (CYP)1A1, and CYP2E1 genes with susceptibility to EC as well as their interaction with environmental factors such as smoking and high consumption of salted tea in Kashmir valley.
The results showed that GSTM1 null genotype and GSTT1 null genotype were significantly associated with increased risk for esophageal cancer in Chinese population.
In patients with smoking habits, GSTM1 null and GSTP1 ile/ile genotype were at higher risk for esophageal cancer (OR 1.5; 95% CI=0.50-4.4 and OR 1.3; 95% CI=0.40-3.5), respectively.
Gene-environment interaction analysis showed that CYP1A1 Val/Val genotype, GSTM1 deletion genotype had synergetic interactions with tobacco smoking, alcohol drinking and family history of EC.
These findings suggest the GSTM1 polymorphism is involved in the susceptibility to esophageal cancer development, and tea consumption reduces the risk of esophageal and stomach cancers.
These results are consistent with the notion that exposure to environmental carcinogens that are detoxified by GSTM1, such as polycyclic aromatic hydrocarbons, may contribute to the etiology of esophageal cancer in Linxian.
We studied the frequencies of polymorphic variants in CYP1A1, GSTP1, GSTT1, and GSTM1 genes in 98 patients with Barrett's epithelium and 34 patients with esophageal cancer.
We investigated the genetic polymorphisms of CYP1A1, CYP2E1 and GSTM1 in Japanese esophageal cancer patients (n = 53) with a histological diagnosis of squamous-cell carcinoma, to determine whether susceptibility to esophageal cancer is associated with these polymorphisms.