Polymorphisms of the DNA repair gene xeroderma pigmentosum group A and risk of primary lung cancer.

Polymorphisms in DNA repair genes may be associated with differences in the repair capacity of DNA damage and may influence an individual's susceptibility to smoking-related cancer. We investigated the association between two polymorphisms of the DNA repair gene XPA and risk of lung cancer in the Korean population. Two XPA polymorphisms (A23G and G709A) were typed in 265 lung cancer patients and 185 healthy controls who were frequency-matched on age and sex. The XPA G709A polymorphism was not detected in cases and controls. The XPA 23 GG genotype was associated with a significantly decreased risk for lung cancer [odds ratio (OR), 0.56; 95% confidence interval (CI), 0.35-0.90] when the combined AA and AG genotype was used as the reference. The reduction in risk for the XPA 23 GG genotype was significant in males (OR, 0.51; 95% CI, 0.30-0.86), younger individuals (OR, 0.39; 95% CI, 0.19-0.80), and current smokers (OR, 0.46; 95% CI, 0.25-0.83). These results suggest that the XPA A23G polymorphism contributes to genetic susceptibility for lung cancer.