title: Helicobacter pylori and gastric carcinogenesis.
abstract: BACKGROUND
  Helicobacter pylori causes chronic persistent gastritis in virtually all infected subjects, leading to development of atrophic gastritis, intestinal metaplasia and eventually dysplasia and gastric cancer in a number of infected subjects. Based on the available evidence, an IARC monograph committee classified H. pylori as a class I carcinogen to humans. Prospective studies suggest that infection increases the risk for atrophic gastritis and gastric cancer at least 8-fold. In the presence of infection, the risk for atrophy and cancer seems higher if a subject becomes infected in early childhood, if infection occurs with a cagA positive strain, and if acid output is decreased.
  
  
  CONCLUSIONS
  H.pylori is a gastric carcinogen. The clinical implications and possible strategies for cancer prevention have to be delineated in the near future.
authors.affiliation: Dept. of Gastroenterology, Free University Hospital, Amsterdam, The Netherlands.
authors.forename: E J
authors.initials: EJ
authors.lastname: Kuipers
authors.forename: S G
authors.initials: SG
authors.lastname: Meuwissen
mesh_terms: D016481:Helicobacter Infections / Q000150:complications* / Q000175:diagnosis; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D008403:Mass Screening; D011379:Prognosis; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000209:etiology / Q000517:prevention & control