title: Interferon-γ polymorphism and hepatocellular carcinoma susceptibility: a meta analysis.
abstract: BACKGROUND
  Interferon-gamma (IFN-γ) was first defined as an antiviral agent with potent antitumor effects in 1957 and this is supported by much subsequent research. IFN-γ rs2430561 polymorphism was found to increase IFN-γ production involved in the regulation of immune system. Previous studies of rs2430561 genotypes and hepatocellular carcinoma (HCC) susceptibility have produced inconsistent results. We thus summarized all epidemiologic and molecular data and carried out a meta-analysis to evaluate the effects of this functional polymorphism on HCC incidence.
  
  
  METHODS
  Human hospital- or population-based studies were identified by searching multiple databases (BIOSIS, Embase, PubMed, Web of Science, Chinese Biomedical Literature database). Six studies were selected for the meta-analysis. Crude ORs was calculated assuming the allele, homozygote, heterozygote, dominant and recessive model. The stability and reliability of the combined results were examined by using sensitivity analysis and publication bias tests.
  
  
  RESULTS
  Meta-analysis under the allele model showed that the T allele compared with the A allele showed a moderately but nonsignificantly increased risk of HCC (OR = 1.12, 95% CI = 0.92-1.35). Analyses under the remaining models revealed no evidence of a significant association. In subgroup analysis by infection type, summary ORs suggested no significantly elevated risk of HBV-infected HCC in relation to the allele or genotypes of rs2430561 polymorphism. The combined results were reliable according to sensitivity analysis and publication bias tests.
  
  
  CONCLUSIONS
  We found no strong evidence supporting a statistically significant association between IFN-γ rs2430561 polymorphism and HCC susceptibility.
authors.affiliation: Department of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University Chongqing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University Chongqing, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Liao
authors.affiliation: Department of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University Chongqing, China.
authors.forename: Yuefei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Hepatobiliary Surgery, Southwest Hospital, Third Military Medical University Chongqing, China.
authors.forename: Leida
authors.initials: L
authors.lastname: Zhang
keywords: Interferon-gamma; hepatocellular carcinoma; polymorphism; susceptibility