Chronological changes of characteristics of early gastric cancer and therapy: experience in the Cancer Institute Hospital of Tokyo, 1950-1994.

Gastric cancer, the leading cause of death from cancer in Japan, has long been studied. We received our first patient with early gastric cancer in 1950 and have since treated 2382 patients with this cancer up to 1990. The percentage of early gastric cancers diagnosed has been on the increase following the improvement in diagnostic skills and the establishment of mass screening. At present, more than half of the gastric cancers presenting are in the early stages. Chronological changes in diagnoses of early gastric cancer are characterized by the increased findings of (a) small tumors less than 4 cm in diameter (b) depressed-type carcinoma (c) lesions of the upper part of the stomach, and (d) undifferentiated-type adenocarcinoma. The standard method of treatment for early gastric cancer was standard radical operation in the 1970s. In the 1980s endoscopic mucosal resection and limited operation were adopted and their use has been increasing annually. The prognosis for early gastric cancer is quite favorable (the 5-year survival rate is more than 90%), and it is regarded as a disease with good prognosis. To obtain still better therapeutic results, it is essential to increase the proportion of early gastric cancers where endoscopic mucosal resection or limited operation is indicated, and improve the techniques of those procedures.