title: Association between infections with CagA-positive or -negative strains of Helicobacter pylori and risk for gastric cancer in young adults. Research Group on Prevention of Gastric Carcinoma Among Young Adults.
abstract: OBJECTIVE
  We assessed the association between infection with CagA-positive and -negative Helicobacter pylori and the risk of gastric cancer in young adults.
  
  
  METHODS
  CagA IgG antibodies were measured in sera of subjects participating in a case-control study in Japan. The study subjects were 103 gastric cancer patients <40 yr of age, 100 inpatients with benign diseases, and 101 screenees younger than age 43 yr.
  
  
  RESULTS
  Compared with the H. pylori-negative/CagA-negative (H. pylori-/CagA-) group, both the H. pylori-positive/CagA-negative (H. pylori+/CagA-) group and the H. pylori-positive/CagA-positive (H. pylori+/CagA+) groups showed elevated odds ratios for intestinal-type, diffuse-type, early, advanced, proximal, and distal gastric cancers. All the relationships were significant except for the H. pylori+/CagA- group in relation to proximal cancer. The overall odds ratios (95% confidence intervals) for gastric cancer in the H. pylori+/CagA- and the H. pylori+/CagA+ groups were 15.0 (6.4, 35.2) and 14.6 (6.7, 31.9), respectively. Between these two groups, no significant difference was observed in risks for intestinal-type, diffuse-type, early, advanced, proximal, or distal gastric cancer.
  
  
  CONCLUSIONS
  In those <40 yr of age, it is concluded that both CagA-positive and CagA-negative H. pylori infections are related to risks of intestinal-type, diffuse-type, early, advanced, and distal gastric cancers.
authors.affiliation: Department of Epidemiology and Environmental Health, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kikuchi
authors.forename: J E
authors.initials: JE
authors.lastname: Crabtree
authors.forename: D
authors.initials: D
authors.lastname: Forman
authors.forename: M
authors.initials: M
authors.lastname: Kurosawa
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D016481:Helicobacter Infections / Q000175:diagnosis / Q000276:immunology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity; D006801:Humans; D007564:Japan; D008297:Male; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000276:immunology / Q000382:microbiology*; D014774:Virulence / Q000235:genetics
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori