Clinical outcomes of endoscopic resection of gastric GIST.

383 Background: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in stomach. We evaluated the long-term clinical outcomes of endoscopic treatment for gastric GISTs. Methods: This is a retrospective study that enrolled 135 cases of gastric subepithelial tumors (SETs) resected by endoscopic procedures and confirmed as GISTs by histopathology from 2005 to 2019. The immediate and long-term clinical outcomes were analyzed retrospectively. Results: The mean age was 57.9 years, and the mean tumor size was 2.1 cm. Of the tumors, 43.0% were located in the corpus, followed by the fundus (26.7%) and cardia (17.0%). Most tumors (85.2%) were resected by endoscopic submucosal dissection. Macroperforation occurred in 4.4% and microperforation in 6.7% of the cases. The R0 resection rate was 15.6%. However, complete resection by the endoscopic view was 90.4%, of which 54.8% were in the very-low-risk group, followed by the low (28.1%), intermediate (11.9%), and high-risk groups (5.2%). During 36.5 months of follow-up, recurrence was found in four (3.4%) of the 118 patients who were monitored for more than six months (low risk group:1/37, 2.7%; intermediate risk group: 2/11, 18.2%; high risk group: 1/6, 16.7%). Conclusions: Endoscopic treatment of a GIST appears to be a feasible procedure in selected cases, however, additional surgery should be considered if pathologic result is corresponding to intermediate or high risk group.