title: ERCC2 polymorphisms and radiation-induced adverse effects on normal tissue: systematic review with meta-analysis and trial sequential analysis.
abstract: BACKGROUND
  The relationship between ERCC2 polymorphisms and the risk of radiotoxicity remains inconclusive. The aim of our study is to systematically evaluate the association between ERCC2 polymorphisms and the risk of radiotoxicity.
  
  
  METHODS
  Publications were identified through a search of the PubMed and Web of Science databases up to August 15, 2015. The pooled odds ratios (ORs) with corresponding 95 % confidence intervals (CIs) were calculated to evaluate the association between ERCC2 polymorphisms and radiotoxicity. Trial sequential analysis (TSA) and power calculation were performed to evaluate the type 1 and type 2 errors.
  
  
  RESULTS
  Eleven studies involving 2584 patients were ultimately included in this meta-analysis. Conventional meta-analysis identified a significant association between ERCC2 rs13181 polymorphism and radiotoxicity (OR = 0.71, 95 % CI: 0.55-0.93, P = 0.01), but this association failed to get the confirmation of TSA.
  
  
  CONCLUSIONS
  The minor allele of rs13181 polymorphism may confer a protect effect against radiotoxicity. To confirm this correlation at the level of OR = 0.71, an overall information size of approximate 2800 patients were needed.
authors.affiliation: Department of Radiation Oncology, the First Hospital of Jilin University, 71 Xinmin Avenue, Changchun, Jilin, China. YuZhe_Song@outlook.com.
authors.forename: Yu-Zhe
authors.initials: YZ
authors.lastname: Song
authors.affiliation: Department of Respiratory Medicine, the First Hospital of Jilin University, Changchun, Jilin, China. duanmn37@icloud.com.
authors.forename: Mei-Na
authors.initials: MN
authors.lastname: Duan
authors.affiliation: Department of Radiation Oncology, the First Hospital of Jilin University, 71 Xinmin Avenue, Changchun, Jilin, China. zhangyuyu173@163.com.
authors.forename: Yu-Yu
authors.initials: YY
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, the First Hospital of Jilin University, 71 Xinmin Avenue, Changchun, Jilin, China. shiyz37@126.com.
authors.forename: Wei-Yan
authors.initials: WY
authors.lastname: Shi
authors.affiliation: Department of Radiation Oncology, the First Hospital of Jilin University, 71 Xinmin Avenue, Changchun, Jilin, China. xiacc37@126.com.
authors.forename: Cheng-Cheng
authors.initials: CC
authors.lastname: Xia
authors.affiliation: Department of Radiation Oncology, the First Hospital of Jilin University, 71 Xinmin Avenue, Changchun, Jilin, China. songyz37@126.com.
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Dong
mesh_terms: D016208:Databases, Factual; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011832:Radiation Injuries / Q000235:genetics*; D051759:Xeroderma Pigmentosum Group D Protein / Q000235:genetics*
chemical_list: D051759:Xeroderma Pigmentosum Group D Protein; C497292:ERCC2 protein, human