Genetic polymorphisms in homologous recombination repair genes that can lead to protein haploinsufficiency are generally associated with increased cancer risk. The aim of the present study was to evaluate associations between the risk of breast cancer and single nucleotide polymorphisms in the genes, encoding three key proteins of the homologous recombination repair: RAD51 (the human homologue of the E. coli RecA protein), X-ray repair cross-complementing group (XRCC) 2 and XRCC3. The polymorphisms studied were G135C of the
RAD51 gene (c. −98 G>C; rs1801320), Arg188His of the
XRCC2 gene (c. 563 G>A; rs3218536), and Thr241Met of the
XRCC3 gene (c. 722 C>T; rs861539). Each polymorphism was genotyped by the PCR-RFLP (restriction fragment-length polymorphism) method in 700 Polish female patients with sporadic breast cancer and in 708 cancer-free women, who served as controls. In the present study, we showed the association between
RAD51 G135C polymorphism and the incidence of breast cancer (
p < 0.0001), but found no significant association with
XRCC2 Arg188His or
XRCC3 Thr241Met polymorphism. Instead, significant association was identified between
XRCC2 Arg188His or
XRCC3 Thr241Met polymorphism and breast cancer progression, assessed by the histological grading. However, each of these three polymorphisms was not associated with the tumor size or the lymph node metastases. This study provides evidence that links single nucleotide polymorphisms of
RAD51 and
XRCC2/3 genes with the risk of breast cancer in Polish women. In conclusion,
RAD51 G135C,
XRCC2 Arg188His and
XRCC3 Thr241Met polymorphisms may be regarded as predictive factors of sporadic breast cancer in female population.
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