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.
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.
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).
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.
Adenocarcinomas are the most frequent cancers of the pancreas and their incidence is increasing . If untreated, adenocarcinomas are fatal in almost all cases . Only a minority of patients (13–22 % in Europe and the US) with pancreatic adenocarcinomas undergo surgical resection, the only potentially curative treatment. The majority receives supportive therapy only . Due to the rapid progression, the relative 5-year relative survival probability (RS) of these patients is approximately 10 % only . The prognosis depends critically on the stage at diagnosis, grading, anatomical subsite and patient’s age .
Pancreatic neuroendocrine neoplasms originate from the neuroendocrine cell lineage. The WHO classification of pancreatic neuroendocrine neoplasms (NEN) was established in 2000 and was updated several times. As of 2019, pancreatic NEN “include malignant well-differentiated NENs, called neuroendocrine tumors (NETs), and poorly differentiated NENs, designated as neuroendocrine carcinomas (NECs)” . Among NETs, a distinction is made between functioning NETs, which manifest with symptoms of hormone excess, and non-functioning NETs that are hormonally inert and lack overt clinical symptoms . Many NETs, especially if they are small or localized in the pancreatic tail, are detected incidentally .
Analyses of US SEER data showed that the incidence of pancreatic NEN has increased, especially since the early 1990 s. The steady increase in the incidence of NEN has been attributed in particular to the result of advanced imaging . The prognosis of these tumors has also improved due to earlier diagnosis and new therapeutic approaches such as somatostatin analogues, molecular targeted therapy, and peptide receptor radionuclide therapies . In England, 2010–2013, NEN could be resected more frequently than adenocarcinomas (e.g. NENs in 35 %, adenocarcinomas in 9 %) .
Because NEN is the second most common cancer of the pancreas and the subgroups of NEN (NET and NEC) may be prognostically distinct, survival analysis distinguishing these groups is important. The aim of this study is to provide population-based morphology and site-specific incidence and relative survival estimates of pancreatic cancer in North Rhine-Westphalia and Saarland, Germany, 2009–2018.