title: Association between TNF-α-308 G/A gene polymorphism and gastric cancer risk: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Tumor necrosis factor-alpha (TNF-α) has been found to be associated with gastric carcinogenesis, but individually published results have been inconclusive. The aim of this study was to explore the relationship between the TNF-α-308 G/A polymorphism and gastric cancer risk.
  
  
  METHODS
  MEDLINE, EMBASE and the COCHRANE library databases were searched for relevant articles to identify all available data. The odds ratios (ORs) with 95% confidence intervals (95% CIs) from each study were used to assess the association between the TNF-α-308 G/A polymorphism and gastric cancer risk.
  
  
  RESULTS
  This meta-analysis included 30 studies (32 datasets) involving 7009 gastric cancer cases and 12,119 control subjects. Overall, a significant association was found between the TNF-α-308 G/A polymorphism and gastric cancer in AA+GA vs. GG (dominant contrast model) (OR=1.20, 95% CI=1.07-1.34, p=0.001). With stratification based on ethnicity, the TNF-α-308 G/A polymorphism was correlated with gastric cancer risk in Caucasians, using the dominant contrast model (OR=0.74, 95% CI=0.57-0.96, p=0.02), but not in East Asians and other ethnic groups. In the comprehensive subgroup analysis, a significant association was also found in recent articles (published after 2005), population-based high-quality studies, hospital-based high-quality studies, studies using the TaqMan method and non-cardia subgroups. However, the TNF-α-308 G/A polymorphism was not associated with specific histological types of gastric cancer risk.
  
  
  CONCLUSIONS
  The TNF-α-308 G/A polymorphism may contribute to susceptibility to gastric cancer in Caucasians, especially for non-cardia gastric cancer, as most strongly demonstrated in high-quality studies and in studies using the TaqMan genotyping method. Furthermore, we recommend the TaqMan method as the preferred genotyping method in DNA polymorphism studies.
authors.affiliation: Division of Upper Gastrointestinal Surgery, Department of Surgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jong-Pill
authors.initials: JP
authors.lastname: Yang
authors.affiliation: Division of Upper Gastrointestinal Surgery, Department of Surgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Myung-Han
authors.initials: MH
authors.lastname: Hyun
authors.affiliation: Division of Upper Gastrointestinal Surgery, Department of Surgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jeong-Min
authors.initials: JM
authors.lastname: Yoon
authors.affiliation: Division of Upper Gastrointestinal Surgery, Department of Surgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Min-Jeong
authors.initials: MJ
authors.lastname: Park
authors.affiliation: Division of Upper Gastrointestinal Surgery, Department of Surgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
authors.forename: Donghyeok
authors.initials: D
authors.lastname: Kim
authors.affiliation: Division of Upper Gastrointestinal Surgery, Department of Surgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea. Electronic address: kugspss@korea.ac.kr.
authors.forename: Sungsoo
authors.initials: S
authors.lastname: Park
mesh_terms: D005006:Ethnicity / Q000235:genetics; D056726:Genetic Association Studies; D018740:Genetic Heterogeneity; D020022:Genetic Predisposition to Disease; D006801:Humans; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D017594:Publication Bias; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D014409:Tumor Necrosis Factor-alpha
keywords: Cytokine; Gastric cancer; Polymorphism; TNF-α-308; Tumor necrosis factor-alpha