Advancements in Endoscopic Treatment for Gastric Subepithelial Tumors.

Peroral flexible endoscopy is a minimally invasive technique that enables the local resection of gastric subepithelial tumors (SETs) with malignant potential. Resection techniques are mainly chosen on the basis of the lesion size. Minute SETs less than 1 cm should be managed through a watch and wait strategy, with the exception of histologically diagnosed superficial lesions, which require endoscopic mucosal resection or endoscopic submucosal dissection. For 1- to 3-cm small SETs, endoscopic enucleation techniques, such as endoscopic submucosal excavation, submucosal tunneling endoscopic resection, and peroral endoscopic tumor resection, can be used. However, endoscopic full-thickness resection is preferred for histologically complete removal with negative surgical margins. When endoscopic full-thickness resection is considered technically difficult, laparoscopic and endoscopic cooperative surgery (LECS) is a safe and dependable alternative. Moderate-sized SETs (3 to 5 cm) require surgical intervention because the lesions must be removed transabdominally. LECS is a less invasive surgical procedure as it reduces the resection area; however, some LECS techniques that require transoral tumor retrieval are not available. Endoscopic intervention for lesions larger than 5 cm should be used with caution for research purposes. With advancements in endoscopic diagnosis, the indications for endoscopic treatment for SETs are expected to improve, thereby enhancing patients' quality of life.