title: Fas -670A/G (rs1800682) polymorphism and digestive cancer risk in Asians: a meta-analysis.
abstract: OBJECTIVE
  Tumorigenesis is a multistep process that begins with the abrogation of normal controls of apoptosis and cell proliferation, and the Fas receptor-ligand system is a key regulator of apoptosis. The Fas -670 A/G single-nucleotide polymorphism (SNP) has been demonstrated to affect the expression of the Fas gene by altering the transcriptional activity in this gene's promoter. However, the association between the Fas -670 A/G polymorphism and digestive cancer risk is still controversial and ambiguous in the Asian population, so we conducted a meta-analysis to confirm and clarify the association between the Fas -670 A/G polymorphism and digestive cancer.
  
  
  METHODS
  A search of PubMed, China National Knowledge Infrastructure (CNKI), and WanFang databases was conducted and encompassed all available articles that had been published up to July 20, 2013. Overall, 15 case-control studies containing 3692 cases and 4895 controls were retrieved based on search criteria for digestive cancer susceptibility related to -670A/G SNP. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of this association.
  
  
  RESULTS
  In the overall analysis, the country type and source of control subgroups, no association between the Fas -670 A/G polymorphism and digestive cancer risk was found. However, in the digestive cancer-type subgroups, a significant protective effect was detected between Fas -670 A/G polymorphism and hepatocellular carcinoma in Asians (AG vs. GG: OR=0.89, 95% CI=0.80-0.99; AA+AG vs. GG: OR=0.93, 95% CI=0.87-1.00).
  
  
  CONCLUSIONS
  Our investigations demonstrated that the Fas -670 A/G polymorphism might decrease the hepatocellular carcinoma risk in Asian populations. Further studies based on larger sample sizes, other ethnicities, and gene-environment interactions should be conducted to further understand the role of Fas -670 A/G polymorphism in digestive cancer risk.
authors.affiliation: 1 Department of Gastroenterology, Tai'an City Central Hospital , Tai'an, China .
authors.forename: Hai-Peng
authors.initials: HP
authors.lastname: Yuan
authors.forename: Qing-Dong
authors.initials: QD
authors.lastname: Liu
authors.forename: Gai-Qin
authors.initials: GQ
authors.lastname: Li
authors.forename: Yan-Qun
authors.initials: YQ
authors.lastname: Cong
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics; D002681:China / Q000453:epidemiology; D005770:Gastrointestinal Neoplasms / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics*; D006801:Humans; D017720:Molecular Epidemiology; D009154:Mutation; D020641:Polymorphism, Single Nucleotide; D019014:fas Receptor / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D019014:fas Receptor