Therapeutic Decision-Making Using Endoscopic Ultrasonography in Endoscopic Treatment of Early Gastric Cancer

Background/Aims: We evaluated the effectiveness of an endoscopic ultrasonography (EUS)-based treatment plan compared to an endoscopy-based treatment plan in select-ing candidates with early gastric cancer (EGC) for endoscopic submucosal dissection based on the prediction of invasion depth. Methods: We reviewed 393 EGCs with differentiated histology from 380 patients who underwent EUS from July 2007 to April 2010. The effectiveness of the EUS-based and endoscopy-based plans was evaluated using a simplified hypothetical treatment algorithm. Results: The numbers of endoscopically determined mucosal, indeterminate, and submucosal cancers were 253 (64.4%), 56 (14.2%), and 84 (21.4%), respectively. Overall, the appropriate treatment selection rates were 75.3 % (296/393) in the endoscopy-based plan and 71.5 % (281/393) in the EUS-based plan (p=0.184). For endoscopic mucosal cancers, the appropriate treatment selection rates in the endoscopy-based plan were 88.1 % (223/253), while the use of an EUS-based plan sig-nificantly decreased this rate to 81.4 % (206/253) (p=0.036). For endoscopic submucosal cancers, the appropriate selec-tion rates did not differ between the endoscopy-based plan (46.4%, 39/84) and the EUS-based plan (53.6%, 45/84) (p=0.070). Conclusions: EUS did not increase the likelihood of selecting the appropriate treatment in differentiated-type EGC. Therefore, EUS may not be necessary before treating differentiated-type EGC, especially in endoscopically pre-sumed mucosal cancers. (Gut Liver 2016;10:42-50) Key Words: Early gastric cancer; Conventional endoscopy; Endosonography; Endoscopic submucosal dissectio