Optimal surgery and lymph node metastasis of duodenal bulbar neuroendocrine neoplasms

Background: There is no consensus on the extent of nodal dissection for duodenal bulbar NENs (neuroendocrine neoplasms).Materials and methods: We constructed and analyzed a combined dataset consisting of the patients who received surgery in our hospital and the patients from the literature based on a systematic review. The incidence, risk factors and location of nodal metastases were examined.Results: Fifty-nine cases including 11 cases managed at our hospital and 48 cases identified from the literature search were examined. Nodal metastasis was observed in 24 patients (40.7%). The 5-year overall survival rate was 100%, regardless of nodal metastasis. Risk factors for lymph node metastasis were tumor size >15 mm and muscularis propria or deeper invasion. Stomach-related lymph node metastasis was found in >20% of patients who were positive for at least one risk factor and 15.4% when patients were negative for both risk factors, while pancreas-related lymph node metastasis was observed in 45.5% of patients who were positive for both risk factors, 7.7% who were only positive for one risk factor, and 0% who were negative for both risk factors.Conclusions: Tumor size and depth of invasion would determine whether the optimal surgery for duodenal bulbar NENs is distal gastrectomy or pancreatico-duodenectomy.(c) 2021 Elsevier Ltd, BASO The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.