Indications for Endoscopic Submucosal Dissection of Early Gastric Cancers

The accepted guideline at the present time for endoscopic mucosal resection (EMR) of early gastric cancer (EGC) is an intramucosal well-differentiated adenocarcinoma 20 mm or less (! 20 mm) in diameter without ulceration. Recent advances in the endoscopic submucosal dissection (ESD) technique, however, now make it possible to resect en bloc larger intramucosal lesions as well as submucosal lesions with minute penetration <= 5500 mu m (SM1), so expanded criteria for endoscopic resection of EGC have been proposed as follows: (1) intramucosal well-differentiated adenocarcinoma without ulceration regardless of lesion size; (2) intramucosal well-differentiated adenocarcinoma with ulceration <= 30 mm in diameter; and (3) SM1 well-differentiated adenocarcinoma 530 mm in diameter. ESD has been specifically developed for the en bloc resection of larger lesions, but it is considerably different and technically more difficult than EMR. The results so far have been highly encouraging, although long-term outcome data are still unavailable.