title: DNA repair pathway genes and lung cancer susceptibility: a meta-analysis.
abstract: OBJECTIVE
  DNA repair pathway genes have been implicated to play an important role in the development of lung cancer. However, contradictory results are often reported by various studies, making it difficult to interpret them. So in this meta-analysis, we have assessed the association between lung cancer risk and two DNA repair pathway genes. XRCC1 and ERCC2, by analyzing 67 published case-control studies.
  
  
  METHODS
  We searched PubMed, Embase and Web of Science using terms "XRCC1" or "XPD" or "ERCC2" and "lung cancer" on August 1, 2012. Three criteria were applied to select included studies for resulting studies. Information was carefully extracted by two investigators independently. We used pooled odds ratio (OR) to assess the effect of a polymorphism, and a dominant model was applied where genotypes that contain the non-reference allele were combined together. All the calculations were performed using STATA version 11.0.
  
  
  RESULTS
  Three common nonsynonymous polymorphisms in XRCC1, codon 194, codon 280 and codon 399, and two common nonsynonymous polymorphisms in ERCC2, codon 312 and codon 751, were analyzed. The result showed in total population, Lys751Gln in ERCC2 is associated with an increase of lung cancer risk, with a summary OR as 1.15. No association was found for any other polymorphisms. When studies were stratified by ethnicity, the risk effect of Lys751Gln in ERCC2 was found only in Caucasians, not in Asians.
  
  
  CONCLUSIONS
  In conclusion, Lys751Gln in ERCC2 is associated with lung cancer, and the risk effect probably exists in Caucasians. By contrast, polymorphisms in XRCC1 are less likely to be susceptible to lung cancer risks.
authors.affiliation: Department of Oncology, Shengjing Hospital of China Medical University, Shenyang 110023, China.
authors.forename: Wusheng
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Oncology, Shengjing Hospital of China Medical University, Shenyang 110023, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Li
authors.affiliation: Department of Oncology, Shengjing Hospital of China Medical University, Shenyang 110023, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Oncology, Shengjing Hospital of China Medical University, Shenyang 110023, China. Electronic address: stroller100@163.com.
authors.forename: Huawei
authors.initials: H
authors.lastname: Zou
mesh_terms: D016022:Case-Control Studies; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D008175:Lung Neoplasms / Q000209:etiology / Q000235:genetics* / Q000378:metabolism; D008957:Models, Genetic; D011110:Polymorphism, Genetic; D000076105:X-ray Repair Cross Complementing Protein 1; D051759:Xeroderma Pigmentosum Group D Protein / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human; D051759:Xeroderma Pigmentosum Group D Protein; C497292:ERCC2 protein, human
keywords: DNA repair pathway genes; Lung cancer; Meta-analysis; Polymorphism