Endoscopic techniques for gastric neuroendocrine tumors: An update

Table 1 Endoscopic therapeutic approaches for the different types of well-differentiated gastric neuroendocrine neoplasms

	Type 1 gNENs (any grade)	Type 2 gNENs (any grade)	Type 3 gNENs (G1)	Type 3 gNENs (G2, G3)
Endoscopic presentation	Small, located in the gastric body or fundus, associated with CAAG	Small, multiple lesions, associated with gastrinoma (MEN1)	Larger, infiltrative, sporadic, single lesions	Larger, infiltrative, sporadic, single lesions
Risk of metastases	< 5%	10%-30%	50%-90%	50%-90%
Suggested resection technique	< 5 mm: Endoscopic surveillance vs excisional biopsy	< 5 mm: Endoscopic surveillance vs excisional biopsy	< 5 mm: Excisional biopsy vs polypectomy	Surgery (regardless of the size)
	5-10 mm: Polypectomy vs EMR (traditional or modified) vs ESD (ESD lower risk of recurrence)	5-10 mm: Polypectomy vs EMR (traditional or modified) vs ESD (ESD lower risk of recurrence)	5-10 mm: Modified EMR vs ESD (no randomized trials)
	> 10 mm: EUS (to make sure it is confined to the submucosal layer, without LNM) + modified EMR vs ESD (no randomized trials)	> 10 mm: EUS (to make sure it is confined to the submucosal layer, without LNM) + modified EMR vs ESD (no randomized trials)	> 10 mm: Surgery vs EUS + ESD (possible role of EFTR)

In case of incomplete resection: hybrid endoscopic mucosal resection/endoscopic submucosal (ESD) or ESD. CAAG: Chronic atrophic autoimmune gastritis; EFTR: Endoscopic full-thickness resection; EMR: Endoscopic mucosal resection; ESD: Endoscopic submucosal dissection; EUS: Endoscopic ultrasound; gNENs: Gastric neuroendocrine neoplasms; LNM: Lymph node metastases; MEN: Multiple endocrine neoplasia.