Progress in studies on early gastric cancer in Japan.

The incidence of gastric cancer in Japan is among the highest in the world. Unremitting efforts have been devoted by many Japanese researchers to improving the situation. They defined and classified early gastric cancer. With the development of diagnostic methods and the prevalence of gastric mass surveys, the rate of diagnosis of early gastric cancer has increased markedly. The five-year survival rate for early gastric cancer at present lies between 90 and 100%. These excellent results have been obtained by the collaboration of radiologists, endoscopists, surgeons and pathologists.