Extrahepatic biliary neuroendocrine tumors: A national cancer database analysis

Highlights•Characterization of extrahepatic biliary neuroendocrine tumors, EBNETs, including factors associated with survival.•Older age, lymph node metastases, and poorly/undifferentiated tumors were associated with worse OS.•Patients with EBNETs experienced abbreviated OS compared to patients with small bowel or pancreas NETs, but improved OS when compared to patients with gallbladder NETs.AbstractBackgroundExtrahepatic biliary neuroendocrine tumors (EBNETs) are rare. We aimed to characterize EBNETs including factors associated with survival.MethodsThe National Cancer Database was queried for patients with EBNETs from 2004 to 2016. Patients who underwent resection were examined using Cox proportional hazards regression and the Kaplan-Meier method. We compared overall survival (OS) among patients with EBNETs to those with NETs from other primary sites.ResultsOverall, 223 patients with EBNETs were identified. Patients were predominantly male (n = 113, 50.7 %), white (n = 177, 79.4 %) and presented without distant metastasis (n = 182, 81.6 %). The majority underwent operation (n = 127, 57.9 %) with resection of the primary tumor (n = 89, 70 %). Among patients who underwent resection (n = 71), multivariable regression demonstrated older age (HR 1.11, 95 % C.I. 1.04–1.17), lymph node metastases (HR 1.19, 95 % C.I. 1.02–1.38) and poorly/undifferentiated tumors [HR 22.3, 95 % C.I. 3.78–131]) were associated with worse overall survival. Patients with EBNETs experienced abbreviated OS compared to patients with small bowel or pancreas NETs (p < 0.001), but improved OS when compared to patients with gallbladder NETs (p = 0.001).ConclusionsTumor differentiation and lymph node status significantly impact overall survival.