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

Objective 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.Methods 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.Results 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+Gin/Gin 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) .Conclusion The XRCC1 Arg194Trp and Arg399Gln may not play an important role in the susceptibility of breast cancer in Chinese women. Key words: Neoplasms,breast; DNA repair; Polymorphism,single nucleotide; Epidemiology,molecular