Objective: To investigate the genetic polymorphism of cytochrome P4502E1 (CYP2E1) as a susceptibility factor for lung cancer in Chinese population.
Methods: The genotype frequencies of RsaI restriction fragment length polymorphisms were analyzed in 92 lung cancer cases and 137 frequency-matched normal controls.
Results: The CYP2E1 c1/c1 genotype was found in 72.8% of lung cancer cases, which was significantly higher (P < 0.01) than that in controls (54.7%). By multivariate analysis, this genotype was found to be associated with a 2.5-fold increased risk of lung cancer (adjusted OR 2.5, 95% CI 1.8-3.8). Stratified analysis suggested an interaction between CYP2E1 c1/c1 genotype and cigarette smoking. The odds ratio (OR) for the CYP2E1 c1/c1 genotype, cigarette smoking and both factors combined was 3.9 (95% CI 1.1-15.2), 4.1 (95% CI 1.1-15.9) and 7.9 (95% CI 2.4-29.4), respectively. The interaction between CYP2E1 c1/c1 genotype and pack-years of cigarette smoking followed the same pattern, with a markedly increased risk in the heaviest smokers.
Conclusion: The CYP2E1 c1/c1 genotype is a susceptibility factor for development of lung cancer in Chinese and there is an apparent gene-environment interaction between the susceptible genotype and cigarette smoking.