Abstract
AIM: To investigate the association between cytochrome P450 2C19 (CYP2C19) gene polymorphism and cancer susceptibility by genotyping of CYP2C19 poor metabolizers (PMs) in cancer patients. METHODS: One hundred and thirty-five cases of esophagus cancer, 148 cases of stomach cancer, 212 cases of lung cancer, 112 cases of bladder cancer and 372 controls were genotyped by allele specific amplification-polymerase chain reaction (ASA-PCR) for CYP2C19 PMs. The frequencies of PMs in cancer groups and control group were compared. RESULTS: The frequencies of PMs of CYP2C19 were 34.1%(46/135) in the group of esophagus cancer patients, 31.8%(47/148) in the stomach cancer patients, 34.4%(73/212) in the group of lung cancer patients, only 4.5%(5/112) in the bladder cancer patients and 14.0%(52/372) in control group. There were statistical differences between the cancer groups and control group (esophagus cancer, chi(2)=25.65, P<0.005, OR=3.18, 95%CI=2.005-5.042; stomach cancer, chi(2)=21.70, P<0.005, OR=2.86, 95%CI=1.820-4.501; lung cancer, chi(2)=33.58, P<0.005, OR=3.23, 95%CI=1.503-6.906; bladder cancer, chi(2)=7.50, P<0.01, OR=0.288, 95%CI=0.112-0.740). CONCLUSION: CYP2C19 PMs have a high incidence of esophagus cancer, stomach cancer and lung cancer, conversely they have a low incidence of bladder cancer. It suggests that CYP2C19 may participate in the activation of procarcinogen of esophagus cancer, stomach cancer and lung cancer, but may involve in the detoxification of carcinogens of bladder cancer.