title: Updated meta-analysis of the association between CYP2E1 RsaI/PstI polymorphisms and lung cancer risk in Chinese population.
abstract: BACKGROUND
  A number of studies have reported relationships of CYP2E1 RsaI/PstI polymorphisms with susceptibility to lung cancer in Chinese population. However, the epidemiologic results have been conflictive rather than conclusive. The purpose of this study was to address the associations of CYP2E1 RsaI/PstI polymorphisms with lung cancer risk in Chinese population comprehensively.
  
  
  METHODS
  Systematic searches were conducted in the PubMed, Science Direct, Elsevier, CNKI and Chinese Biomedical Literature Databases. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to estimate the strength of association.
  
  
  RESULTS
  Overall, we observed a decreased lung cancer risk among subjects carrying CYP2E1 RsaI/PstI c1/ c2 and c1/c2+c2/c2 genotypes (OR=0.76, 95%CI: 0.64-0.90 and OR=0.78, 95%CI: 0.66-0.93, respectively), as compared with subjects carrying the c1/c1 genotype. In subgroup analysis, we observed a decreased lung cancer risk among c1/c2 carriers in hospital-based studies (OR=0.81, 95%CI: 0.68-0.98) and among carriers with c1/ c2 and c1/c2+c2/c2 genotypes in population-based studies(OR=0.57, 95%CI: 0.42-0.79 and OR=0.58, 95%CI: 0.43-0.79, respectively), as compared with subjects carrying the c1/c1 genotype. Limiting the analysis to studies with controls in Hardy-Weinberg equilibrium (HWE), we similarly observed a decreased lung cancer risk among c1/c2 and c1/c2+c2/c2 carriers (OR=0.73, 95%CI: 0.60-0.88 and OR=0.73, 95%CI: 0.60-0.88, respectively), as compared with c1/c1.
  
  
  CONCLUSIONS
  Our results suggested that CYP2E1 RsaI/PstI c1/c2 and c1/c2+c2/c2 variants might be a protective factor for developing lung cancer in Chinese population. Further well-designed studies with larger sample size are required to verify our findings.
authors.affiliation: Department of Toxicology, Henan Center for Disease Control and Prevention, Zhengzhou, China E-mail : wangyd76@163.com.
authors.forename: Ya-Dong
authors.initials: YD
authors.lastname: Wang
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Yang
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.forename: Hai-Yu
authors.initials: HY
authors.lastname: Wang
mesh_terms: D044466:Asian People / Q000235:genetics*; D016022:Case-Control Studies; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012306:Risk; D012307:Risk Factors
chemical_list: D019392:Cytochrome P-450 CYP2E1