Objective: To study the relationship between aldehyde dehydrogenase-2 (ALDH2) and cytochrome P450 2E1 (CYP2E1) gene polymorphism and alcohol drinking habit with the susceptibility of hepatocellular carcinoma( HCC).
Methods: 300 cases of HCC and 292 controls were genotyped for the ALDH2 and CYP2E1 polymorphisms by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.
Results: The frequencies of ALDH2 and CYP2E1 variant genotypes in cases and controls were 50.3%, 48.0% and 32.3%, 32.9%, respectively. There was no significant difference of ALDH2 and CYP2E1 genotypes distribution between cases and controls (P > 0.05). The risk for liver cancer was 3.334 times higher in alcoholics ( > or =3 times drinking per week) with ALDH2 * 2 genotype than that that in cases carrying ALDH2 * 1 genotype while drinking less than 3 times per week (95% CI = 1.746 - 6.406) , and the risk for liver cancer was 1.803 times higher in alcoholics ( > or =3 times drinking per week) with CYP2E1c2 genotype than that in cases carrying CYP2E1cl genotype while drinking less than 3 times per week (95% CI = 0.974 - 3.336). Haplotype of the two genotypes increased liver cancer risk to 1.200 folds (95% CI = 0.730 - 1.972), and interaction between drinking and genotypes increases risk of liver cancer to 1.816 folds (95% CI = 0.985 - 3.348).
Conclusion: ALDH2 or CYP2E1 genotypes alone render no significant risk for HCC, while frequent alcoholic consumption together with ALDH2 or CYP2E1 variant genotypes are associated with risk of hepatocarcinogenesis, suggesting a gene-environment interaction in increasing risk for HCC among Guangxi residents.