title: Genetic polymorphisms of xeroderma pigmentosum group D and prostate cancer risk: a meta-analysis.
abstract: BACKGROUND
  The Xeroderma pigmentosum group D (XPD, also referred to as excision repair cross complementing gene 2, ERCC2) is one of key genes involved in nucleotide excision repair and two potentially functional polymorphisms of XPD (Asp312Asn and Lys751Gln) have been widely investigated in various cancers including prostate cancer. However, the results were conflicting rather than conclusive.
  
  
  OBJECTIVE
  Thus, we conducted a meta-analysis to evaluate the associations between these two polymorphisms of XPD and the risk of prostate cancer.
  
  
  METHODS
  An electronic search of PubMed and Embase was conducted to select relevant studies. Studies containing available genotype frequencies of XPD Asp312Asn and Lys751Gln were chosen, and the associations were assessed by pooled odds ratios with 95% confidence intervals.
  
  
  RESULTS
  According to PubMed and Embase databases, we identified seven eligible studies from six articles, including 2641 cases and 3259 controls for Asp312Asn and nine eligible studies from eight articles, including 3255 cases and 3654 controls for Lys751Gln. The meta-analysis showed that no overall association was observed between XPD Asp312Asn and prostate cancer risk. However, the significantly increased risk of 312Asp allele was found among Asians and Africans, but it seemed to be protective in Caucasians when stratified by ethnicity. For XPD Lys751Gln, overall findings had implicated null effects.
  
  
  CONCLUSIONS
  These findings indicated that the Asn allele of XPD Asp312Asn might be a risk-factor for developing prostate cancer among Asian and African men but protective for Caucasian population.
authors.affiliation: Department of Epidemiology and Biostatistics, Ministry of Education Key Lab for Modern Toxicology, School of Public Health, Nanjing, China.
authors.forename: Hongcheng
authors.initials: H
authors.lastname: Zhu
authors.forename: Songyu
authors.initials: S
authors.lastname: Cao
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiangxiang
authors.initials: X
authors.lastname: Ding
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Wu
authors.forename: Hongxia
authors.initials: H
authors.lastname: Ma
mesh_terms: D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D011471:Prostatic Neoplasms / Q000235:genetics*; D051759:Xeroderma Pigmentosum Group D Protein / Q000235:genetics*
chemical_list: D051759:Xeroderma Pigmentosum Group D Protein; C497292:ERCC2 protein, human