[Endoscopic treatment of early upper gastrointestinal carcinoma--high-frequency-current polypectomy, laser, and microwave coagulation procedures].

The authors have been treating early gastric carcinoma endoscopically by high-frequency-current polypectomy since 1976, by microwave coagulation since 1982, and by laser coagulation since 1983. In order to achieve absolute curability of early carcinoma, we recommend that polypectomy be performed first, whenever possible. The reason for this is that the resected polypectomised tissue enables a decision to be made as to whether further treatment is necessary, after histopathological examination of the specimen. Otherwise, cases in which snaring is impossible, such as flat or depressed carcinomas of markedly small or large size, should be treated by microwave and/or laser coagulation. In total, we have experienced 92 lesions (83 cases) of early gastric carcinoma treated by all of above 3 methods, and we currently have 5 cases showing more than 5-year survival. Among these, type II a early carcinomas less than 10mm in diameter accounted for the majority; on the other hand, there were 11 type II c cases, also with tumors less than 10mm in diameter. Referring to our surgical data, type II c (without ulcer nor lymph node metastases) less than 5mm in size is limited to the mucosa in 100% of cases, and of 6-10mm in size in 85%. We therefore propose that type II c tumors less than 10mm in size should be treated endoscopically, as well as type II a tumors of the same size. In order to determine the depth of carcinomatous invasion, endoscopic ultrasonography (EUS) is effective. The diagnostic accuracy for Ul(-) early carcinoma is almost 100%, but for Ul(+) cases EUS is not so accurate. Further studies and improvements of EUS are thus needed.