Background: Gastroenteropancreatic (GEP) neuroendocrine neoplasms (NENs) comprise a group of rare malignant tumours with heterogeneous behaviour. This study aimed to assess long-term survival and prognostic factors associated with survival, in order to optimise counselling. Patients and methods: This population-based study included all GEP-NENs diagnosed between 1989 and 2016 in the Netherlands, selected from the Netherlands Cancer Registry. Overall survival (OS) and relative survival (RS) were calculated. A Cox Proportional Hazard analysis was used to identify prognostic factors (gender, age, tumour stage, location and treatment) for OS. Analyses were stratified by metastatic disease status and tumour grade. Results: In total, 9697 patients were included. In grade 1, 2 and 3 non-metastatic GEP-NENs (N = 6544), 5-year OS and RS were 81% and 88%, 78% and 83%, and 26% and 30%, respectively. In grade 1 non-metastatic GEP-NENs 10-year OS and RS were 68% and 83%. In grade 1, 2 and 3 metastatic GEP-NENs (N = 3153), 5-year OS and RS rates were 47% and 52%, 38% and 41%, and 5% and 5%, respectively. The highest (relative) survival rates were found in appendicular and rectal NENs, demonstrating 10-year OS and RS of 87% and 93%, and 81% and 95%, respectively. Conclusions: These long-term follow-up data demonstrate significant differences in survival for different grades, tumour stage, and primary origin of GEP-NENs, with the most favourable overall and RS rates in patients with non-metastatic grade 1 appendicular and rectal NENs. This study demonstrates unique long-term OS and RS rates using combined stratification by tumour site, grade and stage.
Bibliographical noteFunding Information:
EJMS has served as an advisory board member for Amgen, Lilly, Novartis and AstraZeneca, has received institutional research funding from AstraZeneca, Pfizer, Novartis and Bayer, and has received non-financial support from Biocartis and Abbvie. All outside the submitted work.
FAV has received consultancy fees from Sanofi and EISAI, speaker honoraria from Sanofi and research support from EISAI. All outside the submitted work.
AMEW reports institutional research grants and study funding from IPSEN, Novartis, Abbvie, BMS, Genzyme, Karyopharm Therapeutics, Roche and Polyphor. All outside the submitted work.
SMEG has received institutional research funding from Roche, Pfizer, Novartis, and Eli Lilly. All outside the submitted work.
JdV has served as a consultant for Amgen, AstraZeneca, MSD, Pierre Fabre and Servier, and has received institutional research funding from Servier. All outside the submitted work.
© 2022 The Author(s)