What types of early gastric cancer are indicated for endoscopic ultrasonography staging of invasion depth?

Figure 3 Flowchart of endoscopic ultrasonography diagnostic strategy for early gastric cancer. EUS should be considered performing the following lesions: (1) differentiated-type cancers without UL diagnosed as invading to SM2; and (2) undifferentiated-type cancers diagnosed by conventional endoscopy as meeting the expanded-indication criteria for endoscopic resection. In cases rather than those lesions, however, EUS may not be needed for the preoperative determination of the depth of EGCs. SM2 indicates invasion ≥ 500 μm into the submucosal layer. EGC: Early gastric cancer; EUS: Endoscopic ultrasonography.