Polymorphisms of DNA repair gene XRCC1 codon194 and its susceptibility to lung cancer

Objective To explore the relationship between the polymorphisms of DNA repair gene XRCC1 codon194 and the susceptibility to lung cancer. The possible interaction between XRCC1 and tobacco smoking with the risk of lung cancer was also evaluated. Methods A case-control study including 396 newly diagnosed lung cancer cases and 465 healthy resident controls was conducted. We employed the PCR-based restriction fragment length polymorphism (RLFP) techniques to analyze the XRCC1 polymorphisms at Arg194Trp loci. Logistic regression was used in the analysis of the relationship of this polymorphism to lung cancer susceptibility. Results The frequency of allele Arg and Trp was 69.82% and 30.18% in case group, and 74.30% and 25.70% in the control group, respectively; a statistical significant difference was observed (P= 0.038 6). The carriers of Trp/Trp had higher risk of lung cancer than Arg/Arg carriers, adjusted OR was 1.72 (95% CI: 1.05-2.80). Smokers carrying Trp/Trp genotype had higher risk than nonsmokers with Arg/Arg genotype (OR = 7.18, 95%CI:3.09-16.66). Among smokers, the Trp/Trp carriers also possessed higher risk relative to Arg/Arg carriers (OR = 2.02, 95%CI: 0.92-4.43). Conclusions The results suggest that genetic polymorphism of DNA repair gene XRCC1 codon194 might play an important role in lung cancer susceptibility. Furthermore, XRCC1 may interact with tobacco smoking and increase the risk of lung cancer.