President of the 33rd Annual Congress of Japanese Society of Gastroenterological Endoscopy

ADVANCES IN ENDOSCOPIC DIAGNOSIS AND TREATMENT OF EARLY GASTRIC CANCERS

Abstract

Endoscopic biopsy under direct vision of gastrofiberscope made it possible to diagnose the gastric cancers in the early stage. Even by this method, however, it is still difficult to determine the exact extent and depth of involvement of gastric cancer. Therefore, in order to diagnose early gastric cancers more exactly, many new endoscopic procedures such as chromoendoscopy, laser endoscopy, endoscopic ultrasonography were developed. Furthermore, new endoscopic procedures for treatment of early gastric cancers such as injections of ethanol or anti-cancer agents, endoscopic polypectomy and endoscopic treatment using laser light were developed. These new endoscopic techniques and tools may bring about good results in more early detection and complete cure of early gastric cancers. In the present paper, the development and/or improvement of endoscopic procedures for endoscopic diagnosis and treatment of early gastric cancers in our hospital are reviewed. The following results are obtained; A) Advances in endoscopic diagnosis of early gas-tric cancers 1. According to the gross characteristic finding of the tumor, we subdivided early gastric cancers of type I into molar and non-molar types, and that of type IIc into tumors with and without converging folds. This macroscopic classification of early gastric cancers was very useful for diagnosis of depth of involvement of the tumors and determination of the target sites of endoscopic biopsy. Since 1961, 1, 500 cases of early gastric cancers were found in our hospital. Mucosal cancers, cancers located in the upper portion of the stomach and small cancers less than 10 mm in the longest diameter were found in increasing frequencies. 2. Endoscopic television and electronic endoscopy made it posible to simultaneously observe the same endoscopic pictures by many endoscopists, and so make accurate diagnosis. Image processing enhanced the ability to discriminate gastric lesions. 3. Chromoendoscopic examinations (Congo red test and Congo red-methylene blue test) developed in our hospital were useful for diagnosis of the extent of early gastric cancers. By the latter test, gastric cancers were observed as areas where both dyes were bleached. 4. New endoscopic procedures using laser light and FITC-labeled monoclonal antibody may be useful for early detection of gastric cancers. 5. Infrared laser angiography was useful for discriminating between the mucosal and submucosal cancers. B) Advances in endoscopic therapy of early gastric cancers 1. Topical injections of absolute ethanol was effective in the treatment of the elevated types of early gastric cancers, although recovery of the specimens was impossible. 2. Photodynamic therapy using hematoporphyrin derivatives and dye laser irradiation was a useful method for treating depressed type of early gastric cancers, especially ulcerated types of the tumor untreatable by the other endoscopic therapies In summary, these tests developed in our hospital permit more accurate detection of suspicious lesions in the early stage, and so the early cancers can be completely cured by the endoscopic treatments.