Epoxide hydrolase Tyr113His polymorphism is not associated with susceptibility to esophageal squamous cell carcinoma in population of North China.

Abstract

To investigate the possible association of microsomal epoxide hydrolase (mEH) Tyr113His polymorphism with susceptibility to esophageal squamous cell carcinoma (ESCC) in a population of North China. The mEH Tyr113His genotypes were determined by polymerase-chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis in 257 patients with esophageal squamous cell carcinoma (ESCC) and 252 healthy subjects as a control group. The frequencies for Tyr and His alleles were 44.2%, 55.8% in ESCC patients, and 44.0% and 56.0% in healthy subjects, respectively. No statistic difference in allele distribution was observed between ESCC patients and controls (chi2=0.008, P=0.929). The overall genotype distribution difference was not observed between cancer cases and controls (chi2=2.116, P=0.347). Compared with Tyr/Tyr genotype, neither His/His genotype nor in combination with Tyr/His genotype significantly modified the risk of the development of ESCC, the adjusted odds ratio was 1.076 (95% CI=0.850-1.361) and 0.756 (95% CI=0.493-1.157), respectively. When stratified for sex, age, smoking status and family history of upper gastrointestinal cancer, His/His genotype alone or in combination with Tyr/His genotype also did not show any significant influence on the risk of developing ESCC. MEH Tyr113His polymorphism may not be used as a stratification marker in screening individuals at a high risk of ESCC.