CYP1A2*1F Gene Variant, Alkaline Salt Tea Intake and Risk of Esophageal Squamous Cell Carcinoma

Unlike many other cancers, the relationship of CYP1A2*1F (rs762551) polymorphism with esophageal squamous cell carcinoma (ESCC) risk has not been assessed so far. To evaluate its association with ESCC, we conducted a case control study in Kashmir, India, a high risk region. We recruited 404 histopathologically confirmed ESCC cases and 404 controls, individually matched for sex, age and residence to the respective cases. Information was obtained on dietary, lifestyle and environmental factors in face to face interviews using a structured questionnaire from each subject. Genotypes were analyzed by polymerase chain reaction, restriction fragment length polymorphism and sequencing randomly selected samples. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs). We found that mutant genotype (AA) of CYP1A2*1F polymorphism was associated with ESCC risk (OR = 3.11; 95% CI: 1.72-5.36). A very strong ESCC risk was observed in subjects who drank >1250 ml of salt tea daily and harbored mutant genotype of CYP1A2*1F (OR = 14.51; 95% CI: 5.33-39.47). The study indicates that CYP1A2*1F polymorphism is associated with ESCC risk and the risk is modified in salt drinkers. However, more replicative and mechanistic studies are needed to substantiate the findings.