Helicobacter pylori causes chronic active inflammation of the gastric
mucosa in the majority of infected patients. In a considerable number
of them, this will eventually lead to a loss of gastric glands, and th
us the establishment of atrophic gastritis, This is associated with th
e development of intestinal metaplasia and dysplasia. These consecutiv
e conditions increase the risk for gastric cancer, particularly of the
intestinal type. We reviewed the evidence that H. pylori plays an imp
ortant role in this sequence of events that can lead to gastric cancer
. This paper focuses on the difficulties in staging atrophic gastritis
, the incidence and prevalence of this condition and the relation with
H. pylori infection. Furthermore, it describes the evidence for the r
ole of this organism and gastric mucosal atrophy in the aetiology of g
astric cancer and focuses on the life-time incidence of gastric cancer
in the presence of this bacterium.