Current indications of endoscopic submucosal dissection for early gastric cancer in Japan.

Endoscopic submucosal dissection for early gastric cancer seems to be technically mature. For expanding its indications, the outcomes of endoscopic submucosal dissection must not be inferior to those of surgery, as early gastric cancer is mostly treated by surgery. Therefore, the principles for the indications of endoscopic submucosal dissection are as follows: (1) extremely low possibility of lymph node metastasis as the theoretical condition and (2) suitability for an en-bloc resection as the technical condition. Based on previous positive results, differentiated gastric cancer (>2 cm without ulcer [UL]; ≤3 cm with UL) has become an absolute indication for endoscopic submucosal dissection. Undifferentiated gastric cancer is also expected to become an absolute indication in the future. Thereafter, the complete indications of endoscopic submucosal dissection for early gastric cancer will be available. Further, more expanded indication criteria should be considered especially for elderly patients because invasiveness of gastrectomy.