title: An updated meta-analysis on the association of X-ray repair cross complementing group 1 codon 399 polymorphism with hepatocellular carcinoma risk.
abstract: BACKGROUND
  A number of studies have reported the association of X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism with susceptibility to hepatocellular carcinoma (HCC). However, the results were inconsistent and inconclusive. The aim of this study was to comprehensively explore the association of XRCC1 Arg399Gln variant with HCC risk.
  
  
  METHODS
  Systematic searches of PubMed, Elsevier, Science Direct, CNKI and Chinese Biomedical Literature Database were performed. Pooled odds ratio (OR) with 95% confidence intervals (CI) was calculated to estimate the strength of association.
  
  
  RESULTS
  Overall, we observed an increased HCC risk among subjects carrying XRCC1 codon 399 Gln/Gln, Arg/Gln and Gln/ Gln+Arg/Gln genotypes (OR=1.20, 95%CI: 1.05-1.38, OR=1.16, 95%CI: 1.05-1.28, and OR=1.14, 95%CI: 1.04-1.24, respectively) based on 20 studies including 3374 cases and 4633 controls. In subgroup analysis, we observed an increased risk of XRCC1 codon 399 Gln/Gln, Arg/Gln and Gln/Gln+Arg/Gln polymorphisms for HCC in hospital-based study (OR=1.25, 95%CI: 1.03-1.51, OR=1.21, 95%CI: 1.07-1.36 and OR=1.18, 95%CI: 1.06-1.31, respectively) and in Asian population (OR=1.19, 95%CI: 1.03-1.38, OR=1.17, 95%CI: 1.04-1.30 and OR=1.14, 95%CI: 1.04-1.25, respectively). Limiting the analysis to the studies with controls in agreement with Hardy-Weinberg equilibrium (HWE), we observed an increased HCC risk among Gln/Gln, Arg/Gln and Gln/ Gln+Arg/Gln genotype carriers (OR=1.17, 95%CI: 1.05-1.29, OR=1.12, 95%CI: 1.00-1.25 and OR=1.11, 95%CI: 1.02-1.21, respectively).
  
  
  CONCLUSIONS
  This updated meta-analysis results suggest that XRCC1 Arg399Gln variants may contribute to HCC risk. Well-designed studies with larger sample size were required to further verify our findings.
authors: Henan Center for Disease Control and Prevention, Zhengzhou, China E-mail : wangyd76@163.com, wangyd76@yahoo.com.
authors: Ya-Dong
authors: YD
authors: Wang
authors: Wen-Long
authors: WL
authors: Zhai
authors: Hai-Yu
authors: HY
authors: Wang
authors: Xiang-Qun
authors: XQ
authors: Xia
mesh_terms: D044466:Asian People / Q000235:genetics; D006528:Carcinoma, Hepatocellular / Q000209:etiology* / Q000235:genetics*; D016022:Case-Control Studies; D003062:Codon / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008113:Liver Neoplasms / Q000209:etiology* / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D012306:Risk; D012307:Risk Factors; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D003062:Codon; D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human