title: [Relationship between polymorphisms of DNA repair gene XRCC3 and susceptibility to lung cancer].
abstract: OBJECTIVE
  To study the polymorphisms of DNA repair gene XRCC3 and the relationship between genetic variations and susceptibility to lung cancer.
  
  
  METHODS
  A case-control study of 291 patients with lung cancer and 273 cancer-free subjects as a control group was conducted from September 2006 to January 2007 to detect XRCC3 polymorphisms at loci. Genotypes of XRCC3 were analyzed by real time PCR using Taqman probes.
  
  
  RESULTS
  Compared with never smoking subjects with wild homozygous genotype (Thr/Thr), smokers with the same genotytpe (Thr/Thr) had increased risk of lung cancer, adjusted odds ratio (OR) was 2.467 (95% CI: 1.49 - 4.08, P < 0.001). Smokers with the heterozygous genotype (Thr/Met) also had increased risk of lung cancer, adjusted OR was 2.283 (95% CI: 1.21 - 6.60, P < 0.05). XRCC3 codon 241 homozygous genotype (Thr/Thr) and pack-years of smoking less than 30 had a weak protective effect on adenocarcinoma (OR = 0.49, 95% CI: 0.26 - 0.93, P < 0.05). Allel Met of XRCC3 codon 241 and smoking conferred an increased risk of squamous cell carcinoma (OR = 9.69, 95% CI: 3.27 - 28.72, P < 0.01). Those with allel Met of XRCC3 codon 241 and pack-years of smoking less than 30 or more than 30 had different risk of squamous cell carcinoma, the OR was 8.00 (95% CI: 1.97 - 32.52, P < 0.01), and 11.67 (95% CI: 2.98 - 45.73, P < 0.01) respectively.
  
  
  CONCLUSIONS
  The results demonstrated that genetic polymorphism of XRCC3 DNA repair gene may contribute to the susceptibility to lung cancer and have synergistic effect with smoking.
authors.affiliation: Laboratory of Lung Cancer, Shanghai Pulmonary Hospital, Shanghai, China.
authors.forename: Zeng-Li
authors.initials: ZL
authors.lastname: Zhang
authors.forename: Cai-Cun
authors.initials: CC
authors.lastname: Zhou
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.forename: Liang
authors.initials: L
authors.lastname: Tang
authors.forename: Bo
authors.initials: B
authors.lastname: Su
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D012307:Risk Factors; D012907:Smoking
chemical_list: D004268:DNA-Binding Proteins; C110901:X-ray repair cross complementing protein 3