Objective: The objective of this study is to compare the incidence, demographics, tumor characteristics, and survival between patients with pancreatic neuroendocrine tumors (PNETs) and pancreatic adenocarcinomas.
Materials and methods: Between 2004 and 2012, all cases of pancreatic adenocarcinomas and PNETs were extracted from the population-based cancer registries of the Surveillance Epidemiology and End Results program. To identify the cases, a combination of topographical and histology codes based on ICD-O-3 were used. Incidence, demographics, tumor characteristics, and survival was then compared between these 2 histologic subtypes of pancreatic cancer.
Results: A total of 57,688 patients with pancreatic cancer were identified, of which 53,753 (93%) had pancreatic adenocarcinoma and 3935 (7%) had PNET. The overall age-adjusted incidence of PNETs between 2004 and 2012 was 0.52 per 100,000 per year, whereas that for pancreatic adenocarcinomas during the same period was 7.34 per 100,000 per year. PNETs had a significantly younger median age at diagnosis (61 vs. 69 y). A significant proportion of PNETs were diagnosed at stage I (20.5% vs. 6.0%) and were well differentiated (32.8% vs. 4.5%) compared with adenocarcinomas. Five-year cause-specific survival was 51.3% and 5.0% for PNETs and pancreatic adenocarcinomas, respectively. In multivariate analysis, pancreatic adenocarcinomas had a hazard ratio for death of 4.02 (95% confidence interval, 3.79-4.28) when compared with PNETs.
Conclusions: PNETs present with favorable features such as higher proportion of early-stage tumor, higher proportion of well differentiated tumors, and younger age at diagnosis. PNETs have a significantly better survival than pancreatic adenocarcinomas even after adjusting for age, sex, race, site, grade, and stage.