Background: NAD(P)H:quinone oxidoreductase 1 (NQO1) C609T was reportedly associated with leukemia, lung cancer, colorectal cancer, and urological malignancies. This study was conducted to screen possible cancer sites associated with this polymorphism by a prevalent case-control design.
Methods: The cases were 102 patients with esophageal cancer, 143 with stomach cancer, 74 with colon cancer, 72 with rectal cancer, 192 with lung cancer, 237 with breast cancer, 56 with prostate cancer, and 108 with malignant lymphoma. Controls consisted of outpatients from two sources: 241 noncancer outpatients who underwent gastroscopy and 399 first-visit outpatients, expected to include about 20% with cancer. Genotyping was conducted by polymerase chain reaction with confronting two-pair primers (PCR-CTPP).
Results: The TT genotype with null enzyme activity was found in 19.9% of the 241 noncancer gastroscopy examinees, 16.5% of the 399 first-visit outpatients, 12.7% of the esophageal cancer patients, 16.8% of the stomach cancer patients, 13.5% of the colon cancer patients, 9.7% of the rectal cancer patients, 17.7% of the lung cancer patients, 14.3% of the breast cancer patients, 16.1% of the prostate cancer patients, and 15.7% of the malignant lymphoma patients. The odds ratios (ORs) of the genotypes were not significant for any cancers combined or for any site of cancer, except for lung cancer (OR, 0.66; 95% confidence interval [CI], 0.46-0.96 for CT relative to CC). The OR of current smoking for cancers of the esophagus and lung combined was different between the CC genotype (OR, 2.06; 95% CI, 1.06-3.98) and TT genotype (OR, 5.11; 95% CI, 1.37-19.05), although the difference was not significant.
Conclusion: This study suggests that the CC genotype of the NQO1 C609T polymorphism is associated with the risk of lung cancer, and that the TT genotype increases the risk of smoking for cancers of the esophagus and lung.