title: No association between XRCC1 and XRCC3 gene polymorphisms and breast cancer risk: Iowa Women's Health Study.
abstract: BACKGROUND
  Genetic variation in DNA repair may contribute to differences in the susceptibility of several cancers. We evaluated two polymorphisms in the base excision repair pathway (BER) (XRCC1; Arg194Trp and Arg399Gln) and one polymorphism in the double strand DNA repair pathway (XRCC3; Thr241Met) for their association with breast cancer risk.
  
  
  METHODS
  The association was analyzed in a nested case control study of 460 breast cancer cases and 324 cancer-free controls within the Iowa Women's Health Cohort. DNA was obtained from blood samples or paraffin embedded tissues (PET) and all samples were genotyped by one of three genotyping platforms-PCR-RFLP, PCR-INVADER, or Sequenom.
  
  
  RESULTS
  None of the three polymorphisms studied were significantly associated with breast cancer risk (XRCC1: Arg194Trp (OR=1.21, 95% CI: 0.78-1.88); Arg399Gln (OR=1.20, 95% CI: 0.80-1.79); XRCC3: Thr241Met (OR=1.04, 95% CI: 0.76-1.41).
  
  
  CONCLUSIONS
  These results suggest that independently these polymorphisms of XRCC1 and XRCC3 genes do not contribute significantly to the genetic susceptibility of breast cancer.
authors.affiliation: University of Minnesota, Division of Epidemiology, Suite 300, West Bank Office Building, Minneapolis, MN 55454, United States.
authors.forename: Bharat
authors.initials: B
authors.lastname: Thyagarajan
authors.forename: Kristin E
authors.initials: KE
authors.lastname: Anderson
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Folsom
authors.forename: David R
authors.initials: DR
authors.lastname: Jacobs
authors.forename: Charles F
authors.initials: CF
authors.lastname: Lynch
authors.forename: Archana
authors.initials: A
authors.lastname: Bargaje
authors.forename: Waseem
authors.initials: W
authors.lastname: Khaliq
authors.forename: Myron D
authors.initials: MD
authors.lastname: Gross
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics*; D016022:Case-Control Studies; D015331:Cohort Studies; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D007484:Iowa; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C110901:X-ray repair cross complementing protein 3; C000619371:XRCC1 protein, human