Trend toward a reduced prevalence of Helicobacter pylori infection, chronic gastritis, and gastric cancer in Japan.

It is speculated that declines in H. pylori infection and gastritis over the past few decades may lead to a decline in gastric cancer in Japan, supplemented by excellent procedures for the early detection of gastric cancer. Because H. pylori infection rarely is acquired in adult life, once it is eradicated, reinfection would not be expected in adult patients. It seems likely that adequate treatment of H. pylori infection would provide long-term protection against gastric cancer.