Associations between lung cancer risk and polymorphisms in the DNA repair genes X-ray repair cross-complementing group 1 (XRCC1)

The relationship between lung cancer risk and common polymorphisms in the DNA repair genes X-ray repair cross-complementing group 1 (XRCC1) was examined by a case-control study in a Nanjing population. We found a positive association between lung cancer and XRCC1 codon 399Gln allele (Arg/Gln and Gln/Gln, OR=1.790, 95%CI=1.033-3.103, P=0.038). Subjects with the Arg/Gln genotype for codon 399 had an increased susceptibility to lung cancer compared to subjects with the Arg/Arg genotype (OR=1.893, 95%CI=1.063-3.369, P=0.030). We found no direct association between codon 194Arg/Trp genotype and lung cancer susceptibility (OR=1.040, 95%CI=0.600-1.805, P=0.888). The risk of lung cancer was modified by the amount of smoking -- smokers (smoking index >= 20 pack year) with the 399GIn allele (Arg/Gln + Gln/Gln) had a higher risk (OR=2.536, 95%CI=1.043-6.165) than the nonsmokers without this allele. Our results suggest that polymorphisms of codon 399 in XRCC1 play an important role in susceptibility to lung cancer in Nanjing population.