HELICOBACTER-PYLORI - A TRUE CARCINOGEN

Is Helicobacter pylori a true carcinogen? Most carcinogens are physica l, chemical or viral agents which give rise to the development of neop lasia by inducing alterations in cellular DNA, Evidence for the carcin ogenic potency of such agents is usually based on dose-response curves and animal models and there is often a direct association with (epi-) genetic events, Despite the absence of such data, H. pylori has been designated as a definite cause of human cancer, This designation is la rgely based on epidemiological evidence. H. pylori is a carcinogen in the sense that infection with this organism induces a persistently inf lamed gastric mucosa which is associated with an increased proliferati ve state and an increased gastric cancer risk, As such, 1-2% of the in fected subjects are estimated to develop cancer, with an incidence pro bably close to nine times higher than that among non-infected subjects , There is a need for additional mechanistic knowledge on this associa tion between chronic epithelial inflammation and carcinogenesis. An ad ditional important question is whether H. pylori eradication may contr ibute to gastric cancer prevention, As progressive mucosal abnormaliti es such as atrophy and metaplasia do not regress after such interventi on, the major benefit in terms of cancer prevention is likely to be to infected subjects who have not yet developed permanent gastric mucosa l damage, This is in agreement with data suggesting that the role of H , pylori may be confined to the initial stages of carcinogenesis. Eur J Gastroenterol Hepatol 10:447-450 (C) 1998 Lippincott-Raven Publisher s.