title: Association of CYP2A6*4 with susceptibility of lung cancer: a meta-analysis.
abstract: To assess the association between the variant of Cytochrome P450 2A6 whole gene deletion (CYP2A6*4) polymorphism and risk of lung cancer.
  
  
  
  Two investigators independently searched the PubMed, Elsevier, EMBASE, Web of Science, Wiley Online Library and Chinese National Knowledge Infrastructure (CNKI). Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) for CYP2A6*4 and lung cancer were calculated in a fixed-effects model (the Mantel-Haenszel method) and a random-effects model (the DerSimonian and Laird method) when appropriate.
  
  
  
  This meta-analysis included seven eligible studies, which included 2524 lung cancer cases and 2258 controls (cancer-free). Overall, CYP2A6*4 was associated with the risk of lung cancer (allele*4 vs. allele non-*4, pooled OR  = 0.826, 95% CI  = 0.725-0.941, P-value  = 0.004). When stratifying for population, significant association was observed in Asian (additive model, pooled OR  = 0.794, 95% CI  = 0.694-0.909, P-value  = 0.001; dominant model, pooled OR  = 0.827, 95% CI  = 0.709-0.965, P-value  = 0.016; recessive model (pooled OR  = 0.444, 95% CI  = 0.293-0.675, P-value <0.0001). In the overall analysis, a comparably significant decrease in the frequency of *4/*4 genotype was detected between cases and controls in Asian while no *4/*4 genotype was detected in Caucasian in collected data.
  
  
  
  This meta-analysis suggests that the CYP2A6*4 polymorphism is associated with susceptibility of lung cancer in Asian. The whole gene deletion of CYP2A6 may decrease the risk of lung cancer in Asian samples.
authors.affiliation: Bio-X Institutes and Affiliated Changning Mental Health Center, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, PR China.
authors.forename: Lishan
authors.initials: L
authors.lastname: Wang
mesh_terms: D000483:Alleles; D001189:Aryl Hydrocarbon Hydroxylases / Q000172:deficiency / Q000235:genetics*; D044466:Asian People; D016022:Case-Control Studies; D065637:Cytochrome P-450 CYP2A6; D016206:Databases, Bibliographic; D017353:Gene Deletion; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D007527:Isoenzymes / Q000172:deficiency / Q000235:genetics; D008175:Lung Neoplasms / Q000208:ethnology / Q000235:genetics*; D011110:Polymorphism, Genetic; D044465:White People
chemical_list: D007527:Isoenzymes; D001189:Aryl Hydrocarbon Hydroxylases; C585710:CYP2A6 protein, human; D065637:Cytochrome P-450 CYP2A6