title: Serum Helicobacter pylori CagA antibody as a biomarker for gastric cancer in east-Asian countries.
abstract: OBJECTIVE
  In east-Asian countries, while almost all Helicobacter pylori strains possess the cytotokine-associated gene A (CagA) gene, serum CagA antibody is not detected in some infected subjects. We aimed to clarify the association between anti-CagA antibody and gastric cancer in east-Asian countries.
  
  
  METHODS
  We performed a meta-analysis of case-control studies with age- and sex-matched controls, which provided raw data in east-Asian countries.
  
  
  RESULTS
  Ten studies with a total of 4325 patients were identified in the search. Some reports from Japan, Korea and China showed a positive association between the presence of anti-CagA antibody and gastric cancer; however, the results differed in their various backgrounds. The disparate findings appeared to result from the use of different methods or from variations in the antigens used to detect the anti-CagA antibody. CagA seropositivity was associated with an increased risk of developing gastric cancer.
  
  
  CONCLUSIONS
  Anti-CagA antibody can be used as a biomarker for gastric cancer even in east-Asian countries.
authors.affiliation: Department of Environmental & Preventative Medicine, Oita University Faculty of Medicine, Hasama-machi, Yufu-City, Oita, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Shiota
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsunari
authors.forename: Masahide
authors.initials: M
authors.lastname: Watada
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamaoka
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000097:blood* / Q000276:immunology*; D001426:Bacterial Proteins / Q000097:blood* / Q000276:immunology*; D015415:Biomarkers / Q000097:blood*; D005202:Asia, Eastern; D016481:Helicobacter Infections / Q000453:epidemiology / Q000276:immunology; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D013274:Stomach Neoplasms / Q000097:blood / Q000175:diagnosis*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D015415:Biomarkers; C080866:cagA protein, Helicobacter pylori