title: Glutathione S-transferase T1 (GSTT1) gene polymorphism and gastric cancer susceptibility: a meta-analysis of epidemiologic studies.
abstract: OBJECTIVE
  Studies investigating the association between genetic polymorphism of glutathione S-transferase T1 (GSTT1) and gastric cancer risk have reported conflicting results. Therefore, we conducted this meta-analysis to provide more precise evidence.
  
  
  METHODS
  We searched the databases Medline, PubMed, Embase, and China National Knowledge Infrastructure up to July 30, 2009. Thirty-six studies with 4,357 gastric cancer cases and 9,796 controls were selected. Odds ratio (OR) and 95% confidence intervals (CI) were calculated based on fixed- and random-effects models.
  
  
  RESULTS
  The combined results based on all studies showed there was a significant link between GSTT1 null genotype and gastric cancer risk (OR = 1.14, 95%CI = 1.01-1.28). In subgroup analysis stratified on the basis of ethnic group, we also observed positive association between GSTT1 polymorphism and gastric cancer risk among Caucasians (non-Europeans + non-Americans), but not among East Asians. When stratifying by control source, the overall ORs for population- and hospital-based studies were 1.09 (95%CI = 0.94-1.28) and 1.17 (95%CI = 1.03-1.34), respectively. Subjects with both GSTM1 and GSTT1 negative genotypes had increased gastric cancer risk compared with those who had nonnull genotypes of both GST genes. Subgroup analyses for Helicobacter pylori infection and smoking habit did not reveal any significant association between GSTT1 polymorphism and gastric cancer development.
  
  
  CONCLUSIONS
  This meta-analysis suggests that GSTT1 gene polymorphism may be not associated with increased gastric cancer risk among Europeans, Americans, and East Asians. More large-scale studies based on the same racial group are needed.
authors: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
authors: Bo
authors: B
authors: Chen
authors: Lei
authors: L
authors: Cao
authors: Yong
authors: Y
authors: Zhou
authors: Ping
authors: P
authors: Yang
authors: Hong-Wei
authors: HW
authors: Wan
authors: Gui-Qing
authors: GQ
authors: Jia
authors: Liu
authors: L
authors: Liu
authors: Xiao-Ting
authors: XT
authors: Wu
mesh_terms: D001208:Asia / Q000453:epidemiology; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D005060:Europe / Q000453:epidemiology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D015994:Incidence; D008297:Male; D011110:Polymorphism, Genetic; D011379:Prognosis; D018570:Risk Assessment; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000235:genetics* / Q000473:pathology; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology; D044465:White People / Q000235:genetics
chemical_list: C413545:glutathione S-transferase T1; D005982:Glutathione Transferase