Background: XRCC2 and XRCC3 genes are structurally and functionally related to RAD51 which plays an important role in homologous recombination, the process frequently involved in cancer transformation.
Material and methods: In the present work the distribution of genotypes and frequency of alleles of the RAD51 G135C polymorphism, XRCC2 Arg 188His and XRCC3 Thr241Met polymorphism in 790 cases of breast cancer were investigated. The control group consisted of 798 cancer-free blood donors (age +/- 5 years) who were sex and ethnicity-matched. The polymorphisms were determined by PCR-RFLP methods. We also correlated genotypes with the clinical characteristics of breast cancer patients.
Results: Our results obtained for the 135G>C polymorphism of the RAD51 gene indicated that both the C/C genotype and the C allele are strongly associated with breast cancer. The Arg/His genotype of XRCC2 (OR = 2.16, 95% CI = 1.48-3.16) and Thr/Met of XRCC3 increased the risk of type I breast cancer occurrence (OR = 2.33, 95% CI = 1.60-3.41). We did not find any association with the RAD51, XRCC2/3 gene polymorphism and estrogen and progesterone receptor status.
Conclusion: The results support the hypothesis that the polymorphism of RAD51 and XRCC2/3 gene may be associated with the incidence of sporadic breast cancer in Polish women.