title: TNF-α-308 polymorphism and risk of digestive system cancers: a meta-analysis.
abstract: OBJECTIVE
  To evaluate the association between the tumour necrosis factor alpha-308 (TNF-α-308) gene polymorphism and the risk of digestive system cancers.
  
  
  METHODS
  All eligible case-control studies published up to December 2012 were identified by searching PubMed, Web of Science, Embase and China National Knowledge Internet without language restrictions. The risk of digestive system cancers associated with the TNF-α-308 polymorphism was estimated for each study using odds ratio (OR) together with its 95%CI, respectively. Cochrane Collaboration RevMan 5.1 was used to perform the analysis. A χ²-test-based Q statistic test and an I² test were performed to assess the between-study heterogeneity. When the Q test was significant (P < 0.05) or I² > 50%, the random effects model was used, otherwise the fixed effects model was used.
  
  
  RESULTS
  Fifty-eight studies from fifty-five publications with a total of 9986 cancer patients and 15511 healthy controls were included. Overall, a significant association was found between the TNF-α-308 polymorphism and the risk of digestive system cancers [dominant model: OR = 1.23, 95%CI: 1.09-1.39, (G/A) vs (G/G): OR = 1.15, 95%CI: 1.02-1.28, (A/A) vs (G/G): OR = 1.44, 95%CI: 1.19-1.73, recessive model: OR = 1.38, 95%CI: 1.15-1.66]. Furthermore, when the analysis was stratified by ethnicity, similar results were observed in both the Asian and Caucasian populations, except for the dominant model and heterozygote comparisons in the Asian population [dominant model: OR = 1.24, 95%CI: 0.99-1.56, (G/A) vs (G/G): OR = 1.09, 95%CI: 0.96-1.24]. When the cancer type subgroups were examined, similar results were detected in gastric and hepatocellular carcinomas; however, no significant association was observed among other digestive system cancers.
  
  
  CONCLUSIONS
  The TNF-α-308 gene polymorphism may be significantly associated with the risk of gastric and hepatocellular carcinomas, but not colorectal, pancreatic, or oesophageal cancer, in the Asian population.
authors.affiliation: Xu-Feng Guo, Jun Wang, Shi-Jie Yu, Jia Song, Meng-Yao Ji, Zhuo Cao, Ji-Xiang Zhang, Jing Wang, Wei-Guo Dong, Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Xu-Feng
authors.initials: XF
authors.lastname: Guo
authors.affiliation: Xu-Feng Guo, Jun Wang, Shi-Jie Yu, Jia Song, Meng-Yao Ji, Zhuo Cao, Ji-Xiang Zhang, Jing Wang, Wei-Guo Dong, Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Xu-Feng Guo, Jun Wang, Shi-Jie Yu, Jia Song, Meng-Yao Ji, Zhuo Cao, Ji-Xiang Zhang, Jing Wang, Wei-Guo Dong, Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Shi-Jie
authors.initials: SJ
authors.lastname: Yu
authors.affiliation: Xu-Feng Guo, Jun Wang, Shi-Jie Yu, Jia Song, Meng-Yao Ji, Zhuo Cao, Ji-Xiang Zhang, Jing Wang, Wei-Guo Dong, Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Song
authors.affiliation: Xu-Feng Guo, Jun Wang, Shi-Jie Yu, Jia Song, Meng-Yao Ji, Zhuo Cao, Ji-Xiang Zhang, Jing Wang, Wei-Guo Dong, Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Meng-Yao
authors.initials: MY
authors.lastname: Ji
authors.affiliation: Xu-Feng Guo, Jun Wang, Shi-Jie Yu, Jia Song, Meng-Yao Ji, Zhuo Cao, Ji-Xiang Zhang, Jing Wang, Wei-Guo Dong, Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Cao
authors.affiliation: Xu-Feng Guo, Jun Wang, Shi-Jie Yu, Jia Song, Meng-Yao Ji, Zhuo Cao, Ji-Xiang Zhang, Jing Wang, Wei-Guo Dong, Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Ji-Xiang
authors.initials: JX
authors.lastname: Zhang
authors.affiliation: Xu-Feng Guo, Jun Wang, Shi-Jie Yu, Jia Song, Meng-Yao Ji, Zhuo Cao, Ji-Xiang Zhang, Jing Wang, Wei-Guo Dong, Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Xu-Feng Guo, Jun Wang, Shi-Jie Yu, Jia Song, Meng-Yao Ji, Zhuo Cao, Ji-Xiang Zhang, Jing Wang, Wei-Guo Dong, Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
authors.forename: Wei-Guo
authors.initials: WG
authors.lastname: Dong
mesh_terms: D044466:Asian People / Q000235:genetics; D006528:Carcinoma, Hepatocellular / Q000208:ethnology / Q000235:genetics / Q000276:immunology; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004067:Digestive System Neoplasms / Q000208:ethnology / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D020022:Genetic Predisposition to Disease; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008113:Liver Neoplasms / Q000208:ethnology / Q000235:genetics / Q000276:immunology; D016017:Odds Ratio; D010641:Phenotype; D011110:Polymorphism, Genetic; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000208:ethnology / Q000235:genetics / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D014409:Tumor Necrosis Factor-alpha
keywords: Association; Digestive system cancer; Meta-analysis; Polymorphism; Tumour necrosis factor alpha; rs1800629