DNA repair polymorphisms might contribute differentially on familial and sporadic breast cancer susceptibility: a study on a Portuguese population

Breast Cancer Res Treat. 2007 Jun;103(2):209-17. doi: 10.1007/s10549-006-9364-z. Epub 2006 Oct 25.


The purpose of this study was to evaluate the role of polymorphisms in DNA repair genes as genetic indicators of susceptibility to familial and sporadic breast cancer. We analysed DNA samples from 285 breast cancer patients and 442 control subjects, for XRCC1 Arg399Gln, XPD Lys751Gln, RAD51 G135C and XRCC3 Thr241Met polymorphisms using PCR-RFLP. We observed that women carriers of XRCC1 399Gln genotypes and without family history of breast cancer have a protective effect concerning this disease (OR = 0.54 95% CI 0.35-0.84; p = 0.006). Furthermore, we found that carriers of XRCC3 241Met genotypes without FH have an increased susceptibility of breast cancer (OR = 2.21 95% CI 1.42-3.44; p < 0.001). Additionally, we verified an increased risk of breast cancer in women with FH and carrying RAD51 135C genotypes (OR = 2.17 95% CI 1.19-3.98; p = 0.012). Our results suggest XRCC1 Arg399Gln and XRCC3 Thr241Met DNA repair polymorphisms as important biomarkers to sporadic breast cancer susceptibility, as well as, RAD51 G135C polymorphism as a real risk modifier in familial breast cancer cases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Breast Neoplasms / genetics*
  • DNA Repair / genetics*
  • DNA-Binding Proteins / genetics
  • Female
  • Gene Frequency
  • Genetic Predisposition to Disease*
  • Humans
  • Middle Aged
  • Polymorphism, Genetic*
  • Rad51 Recombinase / genetics
  • X-ray Repair Cross Complementing Protein 1
  • Xeroderma Pigmentosum Group D Protein / genetics


  • DNA-Binding Proteins
  • X-ray Repair Cross Complementing Protein 1
  • XRCC1 protein, human
  • Rad51 Recombinase
  • Xeroderma Pigmentosum Group D Protein
  • ERCC2 protein, human