What remaining questions regarding Helicobacter pylori and associated diseases should be addressed by future research? View from the Far East.

Abstract

Based on the findings of several epidemiological studies, it is believed that Helicobacter pylori infection is closely associated with gastric cancer. Because some abnormalities, such as severe inflammation in the gastric mucosa, impaired secretion of vitamin C, and increased gastric cell proliferation, improve after cure of the infection, anti-H. pylori therapy may reduce the incidence of gastric cancer. In Japan, the odds ratios for the development of atrophic gastritis and gastric cancer in H. pylori-positive patients are not as high as those reported in Europe and the United States. These findings suggest that factors other than H. pylori may exert a considerable influence on the development of atrophic gastritis and gastric cancer in Japan. It is not known whether atrophy and intestinal metaplasia, possible precursors of gastric cancer, are reversible. H. pylori infection is associated with a "gastritis, intestinal metaplasia, and gastric cancer sequence," but it remains obscure whether the infection is directly associated with the development of gastric cancer. We do not know which age group of patients should be given anti-H. pylori therapy for the prevention of gastric cancer. To elucidate whether the eradication of H. pylori can prevent gastric cancer, a Japanese intervention trial is now in progress.