title: XPD Asp312Asn polymorphism and esophageal cancer risk: an update meta-analysis based on 3928 cases and 6012 controls.
abstract: BACKGROUND
  Although xeroderma pigmentosum group D (XPD) was reported to be related with esophageal cancer (EC) risk, the results remained inconsistent. The aim of this meta-analysis was to make a more precise estimation of the relationship between XPD Asp312Asn polymorphism and EC risk.
  
  
  METHODS
  We searched PubMed, Web of Science, Embase, Medline, CNKI and Chinese Biomedical database, covering all publications (up to May, 2014). Statistical analyses were performed with Stata software (version 12.0, USA) and RevMan 5.1 (Copenhagen, 2008). The calculation of odds ratios (ORs) with 95% confidence intervals (CI) was calculated to assess the strength of the association.
  
  
  RESULTS
  A total of 15 case-control studies from 13 literatures including 3928 cases and 6012 controls described Asp312Asn genotypes and EC risk. A significant association between XPD Asp312Asn polymorphism and EC risk was found when all the eligible studies were pooled into this meta-analysis. It's also the same result in subgroup analysis of smokers in dominant model (OR=1.63, 95% CI: 1.06-2.50, P=0.03). However, in the stratified analysis by ethnicity and source of population controls, no association between them was discovered.
  
  
  CONCLUSIONS
  The XPD Asp312Asn polymorphism was proved to contribute to the risk of EC in this meta-analysis. Data showed that tobacco consumption may increase the susceptibility of EC.
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University 9 Zhang Zhi Dong Road, Wuhan 430060, Hubei Province, China.
authors.forename: Xu-Feng
authors.initials: XF
authors.lastname: Guo
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University 9 Zhang Zhi Dong Road, Wuhan 430060, Hubei Province, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University 9 Zhang Zhi Dong Road, Wuhan 430060, Hubei Province, China.
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: Lei
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University 9 Zhang Zhi Dong Road, Wuhan 430060, Hubei Province, China.
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Zeng
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University 9 Zhang Zhi Dong Road, Wuhan 430060, Hubei Province, China.
authors.forename: Xiao-Guang
authors.initials: XG
authors.lastname: Lv
authors.affiliation: Department of Gastroenterology, Renmin Hospital of Wuhan University 9 Zhang Zhi Dong Road, Wuhan 430060, Hubei Province, China.
authors.forename: Wei-Guo
authors.initials: WG
authors.lastname: Dong
keywords: EADC; ESCC; XPD polymorphisms; esophageal cancers; meta-analysis