Strategy of Endoscopic Treatment for Colorectal Tumor: Recent Progress and Perspective

Abstract

In the Colorectal Cancer Treatment Guidelines, the 2005 edition published by the Japanese Society for Cancer of the Colon and Rectum, curative conditions of radical cure based on endoscopically resected specimens of tumors and the selection of treatment methods for colorectal adenoma and early carcinoma were explained in detail. Mucosal lesions can be cured by complete endoscopic resection. On the other hands, submucosal carcinoma showing a positive submucosal (SM) stump, SM invasion for a distance of more than 1000 μm, positive vessel involvement, or poorly differentiated adenocarcinoma/undifferentiated carcinoma should undergo additional surgical resection. In relation to these, we assessed the present situation and perspective of endoscopic submucosal dissection (ESD). The indications for colorectal ESD are as follows. (1) Large size, in which en bloc resection using snare endoscopic mucosal resection is difficult, although it is indicative for endoscopic treatment [laterally spreading tumor of the nongranular type, particularly those of the pseudodepressed type, lesions with V_I type pit pattern, carcinoma with submucosal infiltration, and large lesion with elevated type suspected to be cancer]; (2) mucosal lesions with fibrosis caused by biopsy, peristalsis of the lesions, or chronic inflammations; and (3) local residual early cancer after endoscopic resection.