Wang R, Mohapatra S, Jovani M, et al. - Using the Surveillance Epidemiology and End Result database, researchers undertook this study to assess the prevalence as well as the risk factors of metastasis of nonampullary duodenal neuroendocrine tumors (NAD-NETs) ≤19 mm and also to examine the long-term survival of patients following endoscopic therapy (ET) vs radical surgery. A total of 1,243 patients with T1-2 histologically verified NAD-NETs ≤19 mm in size were included. At the time of diagnosis, metastasis was present in 4.8% of cases, with lower prevalence in ≤10 mm lesions (3.1%) vs 11 to 19 mm lesions (11.7%). Invasion to muscularis propria, age <65 years, submucosal involvement, and 11 to 19 mm in size (vs ≤ 10 mm), all were identified as risk factors for metastases. Between the ≤ 10 mm and 11 to 19 mm groups and the ET vs surgery group, similar 5-year overall survival were reported. The strongest risk factor for metastasis in NAD-NETs was invasion to muscularis propria. When metastasis was not present, in lesions with well/moderate differentiation and without muscle invasion, ET was found to be adequate for NAD-NETs <10 mm and was concluded as a viable choice for 11 to 19 mm lesions.