Ampullary Neuroendocrine Tumors: Insight into a Rare Histology.

Abstract

Ampullary neuroendocrine tumors (NETs) make up < 1% of all gastroenteropancreatic NETs, and information is limited to case series. This study compares patients with ampullary, duodenal, and pancreatic head NETs. The National Cancer Database (2004-2016) was queried for patients with ampullary, duodenal, and pancreatic head NETs. Survival was evaluated using Kaplan-Meier analysis and Cox regression. Overall, 872, 9692, and 6561 patients were identified with ampullary, duodenal, and pancreatic head NETs, respectively. Patients with ampullary NETs had more grade 3 tumors (n=149, 17%) than patients with duodenal (n=197, 2%) or pancreatic head (n=740, 11%) NETs. Patients with ampullary NETs had more positive lymph nodes (n=297, 34%) than patients with duodenal (n=950, 10%) or pancreatic head (n=1513, 23%) NETs. On multivariable analysis for patients with ampullary NETs, age (hazard ratio [HR] 1.03, p<0.0001), Charlson-Deyo score of 2 (HR 2.3, p=0.001) or ≥3 (HR 2.9, p=0.013), grade 2 (HR 1.9, p=0.007) or grade 3 tumors (HR 4.0, p<0.0001), and metastatic disease (HR 2.0, p=0.001) were associated with decreased survival. At 5years, the overall survival (OS) for patients with ampullary, duodenal, and pancreatic head NETs was 59%, 71%, and 50%, respectively (p<0.0001), whereas the 5-year OS for patients with ampullary, duodenal, and pancreatic head NETs who underwent surgery was 62%, 78%, and 76%, respectively (p<0.0001). Ampullary NETs were more likely to present with high-grade tumors and lymph node metastases. Based on the clinicopathologic and survival data, ampullary NETs have a unique underlying biology compared with duodenal and pancreatic head NETs.