Relationship between polymorphisms of X-ray repair cross-complementing group 1 gene Arg194Trp, Arg399Gln and susceptibility of breast cancer

Abstract

To study the relationship between two polymorphisms, Arg194Trp and Arg399Glu, of DNA repair gene X-ray repair cross-complementing group 1 (XRCC1) and the susceptibility of breast cancer in Chinese women. A case-control study with 698 histologically-confirmed female breast cancer cases and 813 cancer-free controls frequency-matched by age and residential area was conducted, and the genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assays. Logistic regression analysis was used to evaluate the odds ratios (ORs) and 95% confidence intervals (CIs) of XRCC1 Arg194Trp and Arg399Glu with susceptibility of breast cancer. A Meta-analysis was used to evaluate the association of Arg399Glu with breast cancer in Chinese women. The genotype frequencies of Arg/Arg, Arg/Trp, Trp/Trp, Arg/Trp + Trp/Trp of XRCC1 gene 194 locus were 48.81% (327/670), 39.85% (267/670), 11.34% (76/670), 51.19% (343/670) in cases and 48.80% (387/793), 41.99% (333/793), 9.21% (73/793), 51.20% (406/793) in controls. Compared to Arg/Arg, the adjusted ORs (95%CIs) were 0.98 (0.75 - 1.28), 1.17 (0.76 - 1.80), 1.09 (0.86 - 1.40). The frequencies of Arg/Arg, Arg/Trp, Trp/Trp, Arg/Gln + Gln/Gln of XRCC1 399 locus were 52.40% (349/666), 38.29% (255/666), 9.31%(62/666), 47.60% (317/666) in cases and 52.22% (412/789), 38.53% (304/789), 9.25% (73/789), 47.78%(377/789) in controls. Compared to Arg/Arg, the adjusted ORs (95%CIs) were 0.93(0.63 - 1.08), 0.96 (0.42 - 1.09), 0.91 (0.62 - 1.05). No significant associations were found between these two polymorphisms and breast cancer risk, also in subgroups stratified by menopause status, history of breast-feed, reproduction and taking oral contraceptives. The overall ORs (95%CIs) of 399 Arg/Trp + Trp/Trp vs Arg/Arg from Meta analysis was 0.97 (0.85 - 1.10). The XRCC1 Arg194Trp and Arg399Gln may not play an important role in the susceptibility of breast cancer in Chinese women.