Background: Interindividual genetic differences in susceptibility to chemical carcinogens are among the most important host factors in human cancer. The present study was undertaken to reveal the association between the polymorphism of CYP2E1 (CYP2E1/PstI and CYP2E1/DraI) with genetic susceptibility to gastric cancer development in Koreans.
Methods: In the present study, 120 gastric cancer patients and 145 controls with no history of tumors were analyzed. CYP2E1 was determined by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP), or PCR and direct gel electrophoresis.
Results: The overall genotype distribution of CYP2E1 was not significantly different from that of controls. However, the genotype distribution of the patient subgroups with a history of heavy cigarette smoking (>30 pack/year) in the CYP2E1/PstI and CYP2E1/DraI polymorphisms were significantly different from those of non-smoking patients (P = 0.0122 and P = 0.0029, respectively). The difference was also noticeable in the younger patient subgroup (aged </=50 years) compared with normal controls (P = 0.0414) in the CYP2E1/PstI. The relative risk estimation for the combination of the CYP2E1/PstI and CYP2E1/DraI polymorphisms revealed that the odds ratio for individuals with homozygotes of rare alleles (c2/c2, C/C) was 5.6 (95% confidence interval = 0.9-39.1).
Conclusions: : These results suggest the possible involvement of the CYP2E1 polymorphism in smoking-induced gastric cancer development in Koreans as one of the risk factors which increases genetic susceptibility.