Outcomes for a Large Cohort of Patients with Rectal Neuroendocrine Tumors: an Analysis of the National Cancer Database

Background Rectal neuroendocrine tumors comprise 20% of neuroendocrine tumors in the alimentary tract, but there is controversy surrounding the optimal management of this disease. The purpose of this study is to better define treatment for patients with rectal neuroendocrine tumors. Methods Using the National Cancer Database, we analyzed patients with rectal neuroendocrine tumors between 2004 and 2015. Patients with metastatic disease and missing treatment data were excluded. We examined overall survival stratified by tumor size, treatment type, and presence of positive lymph nodes using Kaplan-Meier analysis with log-rank test. Cox proportional hazard regression model was performed to identify factors associated with overall survival. Results In total, 17,448 patients with rectal neuroendocrine tumors were identified; 16,531 of these patients met inclusion criteria. The majority of patients had tumors ≤ 10 mm (9216 patients, 79.8%), and approximately 90% underwent local excision. The probability of 5-year overall survival was significantly higher for patients with smaller tumors (≤ 10 mm: 94.1% 11–20 mm: 85.7%, > 20 mm: 71.8%; p