Incidence and relative survival of pancreatic adenocarcinoma and pancreatic neuroendocrine neoplasms in Germany, 2009-2018. An in-depth analysis of two population-based cancer registries.

BACKGROUND:Pancreatic neuroendocrine neoplasms are categorized as neuroendocrine tumors and neuroendocrine carcinomas. Until now, cancer registry reporting of pancreatic cancers does not include a stratification by these two subgroups. We studied the incidence and survival of pancreatic cancer with a special focus on pancreatic neuroendocrine neoplasms. METHODS:We analyzed data from the population-based cancer registries of North Rhine-Westphalia (NRW) and Saarland (SL), Germany, of the years 2009-2018. We included primary malignant pancreatic tumors and report morphology-specific age-standardized (World Standard population) incidence rates for ages 0-79 years and age-standardized relative survival (period approach, ICSS standard). All analyses were restricted to non-death certificate only cases. RESULTS:We analyzed 23,037 patients with a newly diagnosed primary pancreatic cancer. Among morphologically specified cancers, adenocarcinoma (92 %) and neuroendocrine neoplasms (7 %) were the most common morphologies. The age-standardized incidence rates of adenocarcinoma, neuroendocrine tumors and neuroendocrine carcinomas were 4.0-5.5 (in NRW and SL), 0.1-0.3, and 0.1-0.3 per 100,000 person-years, respectively. Neuroendocrine tumors had the highest age-standardized 5-year relative survival with 75.5 % (standard error, SE 2.3) in NRW and 90.6 % (SE 10.2) in SL followed by neuroendocrine carcinomas (NRW: 30.0 %, SE 3.1; SL: 32.3 %, SE 8.7) and adenocarcinomas (NRW: 11.3 %, SE 0.4; SL: 10.2 %, SE 1.5). DISCUSSION:The distinction between neuroendocrine tumors and neuroendocrine carcinomas by the WHO divides neuroendocrine neoplasms into two prognostically clearly distinct subgroups that should be separately analyzed in terms of survival. The first year after diagnosis of pancreatic cancer is the most critical year in terms of survival.