Neuroendocrine Neoplasms of the Esophagus and Esophagogastric Junction in Germany, 2009–2023

Background : The influence of the grading of esophageal neuroendocrine neoplasms (NENs) on prognosis has so far only been investigated in small groups. The aim was to determine the incidence and relative survival of NENs and its subtypes of the esophagus. Methods : We included incident cancers of the esophagus and esophagogastric junction (EGJ) for the years 2009–2023, registered by German cancer registries. NENs were subdivided into neuroendocrine tumors (NETs), neuroendocrine carcinomas (NECs), and mixed forms (MiNENs). To compare the epidemiology of NENs with that of adenocarcinoma and squamous cell carcinoma, we also evaluated these entities in a statistically identical manner. We estimated age-standardized incidence rates (cases per million person-years, old European standard) and 5-year relative survival (period analysis). Results : Of the 2025 NENs of the esophagus and EGJ, 69.9% were NECs, 19.5% were NETs, and 10.7% were MiNENs. 45.0% of NENs occurred at the EGJ. The mean age at diagnosis of esophageal NEN was 67 years. The age-standardized incidence of NEN and the subgroups increased over time, with NEN incidences of 1.1 and 0.4 in 2019 and 2023. Relative survival based on 1320 NENs was 22.8%, with NETs having a markedly better prognosis (59.8%) than NECs (12.5%) and MiNENs falling in between (25.3%). Patients with NET-G1 tumors had a relative survival of 83.8%, while patients with NET-G2 and NET-G3 tumors had relative survival of 50.0% and 9.0%, respectively. Conclusions : Even though accurate diagnosis and coding of NENs is difficult, grading of esophageal NETs has a strong influence on prognosis. Esophageal and esophagogastric NECs have a poorer 5-year relative survival than adenocarcinomas and squamous cell carcinomas.