RESUMEN
BACKGROUND AND AIMS: Nonampullary duodenal neuroendocrine tumors (NAD-NETs) are rare, with limited evidence regarding endoscopic treatment. This study investigated the efficacy and safety of endoscopic resection of well-differentiated NAD-NETs and evaluated long-term outcomes, including local recurrence and metastasis. METHODS: Seventy-eight patients with NAD-NETs who underwent endoscopic resection between January 2011 and August 2022 were included. Clinicopathologic characteristics and treatment outcomes were collected and analyzed. RESULTS: En-bloc resection was achieved for 74 tumors (94.9%) and R0 resection for 68 tumors (87.2%). Univariate analysis identified tumors in the second part of the duodenum, tumor size ≥10 mm, and muscularis propria invasion as risk factors for noncurative resection. Two patients with R1 resection (vertical margin involvement) and 2 patients with lymphovascular invasion underwent additional surgery. Four patients experienced adverse events (5.1%), including 2 cases of delayed bleeding and 2 cases of perforation, all successfully managed conservatively. During a median follow-up period of 62.6 months, recurrence and lymph node metastasis were only detected in 1 patient with R1 resection 3 months after the original procedure. CONCLUSIONS: Endoscopic resection is safe and effective and provides a favorable long-term outcome for patients with well-differentiated NAD-NETs without regional lymph node or distant metastasis.