title: Homologous Recombination Repair Polymorphisms and the Risk for Osteosarcoma.
abstract: BACKGROUND
  DNA repair mechanisms are essential for maintaining genome stability, and genetic variability in DNA repair genes may contribute to cancer susceptibility. Our aim was to evaluate the influence of polymorphisms in the homologous recombination repair genesXRCC3,RAD51, andNBNon the risk for osteosarcoma.
  
  
  METHODS
  In total, 79 osteosarcoma cases and 373 controls were genotyped for eight single nucleotide polymorphisms (SNPs) inXRCC3,RAD51, andNBN. Logistic regression was used to determine the association of these SNPs with risk for osteosarcoma.
  
  
  RESULTS
  None of the investigated SNPs was associated with risk for osteosarcoma in the whole cohort of patients, however, in patients diagnosed before the age of thirty yearsXRCC3rs861539 C>T andNBNrs1805794 G>C were associated with significantly decreased risk for osteosarcoma (P=0.047, OR=0.54, 95% CI=0.30-0.99 andP=0.036, OR=0.42, 95% CI=0.19-0.94, respectively). Moreover, in the carriers of a combination of polymorphic alleles in both SNPs risk for osteosarcoma was decreased even more significantly (Ptrend=0.007). The risk for developing osteosarcoma was the lowest in patients with no wild-type alleles for both SNPs (P=0.039, OR=0.31, 95% CI=0.10-0.94).
  
  
  CONCLUSIONS
  Our results suggest that polymorphisms in homologous recombination repair genes might contribute to risk for osteosarcoma in patients diagnosed below the age of thirty years.
authors.affiliation: Pharmacogenetics Laboratory, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Katja
authors.initials: K
authors.lastname: Goričar
authors.affiliation: Institute of Oncology Ljubljana, Ljubljana, Slovenia.
authors.forename: Viljem
authors.initials: V
authors.lastname: Kovač
authors.affiliation: Oncology and Hematology Unit, University Children's Hospital, University Medical Centre, Ljubljana, Slovenia.
authors.forename: Janez
authors.initials: J
authors.lastname: Jazbec
authors.affiliation: Institute of Oncology Ljubljana, Ljubljana, Slovenia.
authors.forename: Janez
authors.initials: J
authors.lastname: Lamovec
authors.affiliation: Pharmacogenetics Laboratory, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Vita
authors.initials: V
authors.lastname: Dolžan
keywords: DNA repair; osteosarcoma; polymorphism; risk