title: EPHX1 rs2234922 polymorphism and lung cancer susceptibility in Asian populations: a meta-analysis.
abstract: OBJECTIVE
  Polymorphisms of epoxide hydrolase 1 (EPHX1) rs2234922 have been reported to be associated with variations in EPHX1 activity. Many studies have investigated the association between EPHX1 rs2234922 polymorphism and lung cancer risk, but their results have been inconsistent. The purpose of this study was to perform a meta-analysis of all eligible studies to derive a more precise estimation of the associations of EPHX1 rs2234922 polymorphism with lung cancer.
  
  
  METHODS
  The PubMed was searched for case-control studies published up to Oct 01, 2014. Data were extracted and pooled odds ratios (ORs) with 95% confidence interval (CI) were calculated. The pooled ORs for the risk associated with the genotypes of homozygote G/G and G allele carriers (A/G + G/G) with the A/A genotype were calculated. Heterogeneity assumption was checked by the chi-square-based Q-test. A P value greater than 0.10 for the Q-test indicates a lack of heterogeneity among studies, so the pooled OR estimate of the each study was calculated by the fixed-effects model (the Mantel-Haenszel method). Otherwise, the random-effects model (the DerSimonian and Laird method) was used.
  
  
  RESULTS
  In this meta-analysis, we assessed eight published studies involving comprising 1,175 cases and 1,550 controls of the association between EPHX1 rs2234922 polymorphism and lung cancer risk. For the homozygote G/G and G allele carriers (A/G + G/G), the pooled ORs were 1.47 (95% CI: 1.18-1.79, P=0.007 for heterogeneity) and 1.36 (95% CI: 1.14-1.62, P=0.828 for heterogeneity), when compared with the homozygous wild-type genotype (A/A).
  
  
  CONCLUSIONS
  EPHX1 rs2234922 polymorphism contributes to risk of lung cancer among Asian population.
authors.affiliation: Department of Oncology, Wuxi No. 2 People's Hospital, Affiliated to Nanjing Medical University, Wuxi 214002, China.
authors.forename: Xuefang
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Oncology, Wuxi No. 2 People's Hospital, Affiliated to Nanjing Medical University, Wuxi 214002, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Hua
authors.affiliation: Department of Oncology, Wuxi No. 2 People's Hospital, Affiliated to Nanjing Medical University, Wuxi 214002, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Fan
authors.affiliation: Department of Oncology, Wuxi No. 2 People's Hospital, Affiliated to Nanjing Medical University, Wuxi 214002, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Department of Oncology, Wuxi No. 2 People's Hospital, Affiliated to Nanjing Medical University, Wuxi 214002, China.
authors.forename: Xuedan
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Oncology, Wuxi No. 2 People's Hospital, Affiliated to Nanjing Medical University, Wuxi 214002, China.
authors.forename: Jiawei
authors.initials: J
authors.lastname: Zhang
keywords: Epoxide hydrolase 1 (EPHX1); lung cancer; meta-analysis; polymorphism; susceptibility