ABSTRACT
<p><b>OBJECTIVE</b>To explore the relationship between two exonic polymorphisms of DNA repair gene XPC and the susceptibility to lung cancer.</p><p><b>METHODS</b>Genotypes were determined by the primer introduced restriction analysis-PCR(PIRA-PCR) and the PCR-restriction fragment length polymorphism(PCR-RFLP) approaches, respectively, in 320 histologically-confirmed lung cancer cases and 322 age and sex frequency-matched cancer-free controls.</p><p><b>RESULTS</b>Multivariate logistic regression analysis revealed that individuals carrying at least one 499Val variant allele (Ala/Val + Val/Val genotypes) had a significantly increased risk for lung cancer (adjusted OR=1.54; 95%CI: 1.11-2.14), compared with the wild-type genotype (499Ala/Ala). Furthermore, individuals with both putative risk genotypes had a significantly higher risk (adjusted OR=2.55; 95%CI: 1.45-4.52), compared with those with both wild-genotypes. In addition, a potential super multiplicative gene-environment interaction between Ala499Val genotypes and smoking on lung cancer risk was unveiled. The odds ratios of lung cancer for individuals with both putative risk genotypes were 2.63 (95%CI=1.23-5.62) in nonsmokers and 7.36 (95%CI=3.19-17.0) in smokers, respectively.</p><p><b>CONCLUSION</b>These findings support the hypothesis that these two XPC variants may contribute to the risk of developing lung cancer.</p>