Background: The inter-individual differences in upper aerodigestive tract (UADT) cancer risk may be partly attributed to the polymorphic variability in the CYP1A1 gene that is involved in the metabolic activation of xenobiotics to carcinogenic reactive metabolites.
Methods: The hospital-based case-control study evaluated CYP1A1*2A and CYP1A1*2C polymorphisms in 408 histopathologically confirmed cases and 220 controls using polymerase chain reaction-restriction fragment length polymorphism methods.
Results: The multivariate logistic regression analyses demonstrated that CYP1A1 *1A/*2A (odds ratio [OR] 1.76; 95% Confidence interval [CI] 1.19-2.60) and *2A/*2A (OR 2.83; 95% CI 1.43-5.61) genotypes were significantly associated with increased risk for UADT cancers. The gene-environment interaction analyses revealed a significant interaction among tobacco smokers and chewers carrying CYP1A1*2A mutant genotypes on the multiplicative scale.
Conclusion: CYP1A1*2A polymorphic genotypes are associated with an enhanced risk to UADT cancers, in particular, among the habitual tobacco smokers and chewers carrying mutant genotypes in the Tamilians of the Indian population.
(c) 2008 Wiley Periodicals, Inc.