Risk factors for lymph node metastasis and survival of patients with nonampullary duodenal carcinoid tumors treated with endoscopic therapy versus surgical resection: an analysis of the Surveillance, Epidemiology, and End Results program

ABSTRACT Background and aims Endoscopic therapy (ET) have been used to treat nonampullary duodenal neuroendocrine tumors (NAD-NETs) that is ≤10 mm in size, but data on long-term outcomes are limited. In addition, management of 11to 19 mm NAD-NETs is not well defined because of variable estimates of risk of metastasis. We aimed to determine the prevalence and risk factors of metastasis of NAD-NETs ≤19 mm and evaluate the long-term survival of patients after ET as compared with radical surgery. Methods The Surveillance Epidemiology and End Result database was used to identify 1243 patients with T1-2 histologically confirmed NAD-NETs ≤19 mm in size. Cancer-specific survival (CSS) and overall survival (OS) were calculated. Results Overall, 4.8% of cases had metastasis at the time of diagnosis, with lower prevalence in ≤10 mm lesions (3.1%) versus 11 to 19 mm lesions (11.7%), P Conclusion In NAD-NETs, invasion to muscularis propria is the strongest risk factor for metastasis. In the absence of metastasis, in lesions with well/moderate differentiation and without muscle invasion, ET is adequate for NAD-NETs