title: Association of H. pylori infection with gastric carcinoma: a Meta analysis.
abstract: OBJECTIVE
  To follow the principles of evidence based medicine to reach the integrated results of these studies.
  
  
  METHODS
  Twenty-one papers of case-control studies were selected, including 11 on gastric cancer,7 on precancerous lesion of stomach and 3 on lymphoma of stomach. Meta analysis was used to sum up the odds ratios (OR) of these studies.
  
  
  RESULTS
  H. pylori vs gastric cancer (intestinal and diffuse type): the odds ratio from the fixed effect model is 3.0016 (95% CI: 2.4197-3.7234, P<0.001). H. pylori vs precancerous lesion of stomach: a random effect model was used to calculate the summary odds ratio and its value is 2.5635 (95% CI: 1.8477-3.5566, P<0.01). H. pylori vs lymphoma of stomach: though the quantity of literature is too small to make Meta analysis, the data of these 3 studies show that lymphoma of stomach is highly associated with H. pylori infections.
  
  
  CONCLUSIONS
  Since it had been revealed that H. pylori infection pre-exists in gastric carcinoma and precancerous lesions, the results of Meta analysis present a strong evidence to support the conclusion that H. pylori infection is a risk factor for gastric carcinoma.
authors.affiliation: Department of Health Statistics, the Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China. alnico@sohu.com
authors.forename: F B
authors.initials: FB
authors.lastname: Xue
authors.forename: Y Y
authors.initials: YY
authors.lastname: Xu
authors.forename: Y
authors.initials: Y
authors.lastname: Wan
authors.forename: B R
authors.initials: BR
authors.lastname: Pan
authors.forename: J
authors.initials: J
authors.lastname: Ren
authors.forename: D M
authors.initials: DM
authors.lastname: Fan
mesh_terms: D016022:Case-Control Studies; D016481:Helicobacter Infections / Q000150:complications*; D016480:Helicobacter pylori; D006801:Humans; D013274:Stomach Neoplasms / Q000382:microbiology*