Characteristics, management, and outcomes of patients with VIPoma –A retrospective analysis of the ENETS database

Abstract

Introduction: VIPoma is an extremely rare functioning pancreatic neuroendocrine tumor. Therefore, data regarding treatment and outcome are very limited. Aim (s): This multicenter study aimed to analyze clinical characteristics, real‐world management, and outcomes of patients with VIPoma. Methods: Patients with VIPoma treated in a 20‐year period at 14 referral centers for neuroendocrine tumors (NET) were collected in the ENETS Database. Clinical characteristics, therapeutic interventions, and outcomes were analyzed retrospectively. Disease‐free survival (DFS) and overall survival (OS) were estimated using the Kaplan–Meier method. Results: Of 70 patients, 59 (54% male) with a median age of 55 years were included. Forty‐six (78%) patients were diagnosed due to the classical watery diarrhea–hypokalemia–achlorhydria (WDHA) syndrome, and 40 (68%) presented with distant metastases at diagnosis. Fifty‐two (88%) had serum VIP levels >2 times the upper normal limit and the median Ki‐67 index was 5% (range 1%–40%). Surgery of the primary VIPoma was performed in 32 (54%), with curative intent in 22 (37%). In patients with stage I–III disease ( n  = 19), long‐term cure was achieved in only 26% (5/19), with a median DFS of 81 (95%‐CI: 1–215) months and 10‐year OS of 78% (95%‐CI: 61%–100%). In stage IV patients ( n  = 53, 40 at diagnosis, 13 disease progression), the sequence and type of 354 treatment lines varied, while SSA ( n  = 77, 22%), loco‐regional liver‐directed therapy ( n  = 72, 20%), and chemotherapy ( n  = 69, 19%) were most often applied. Median OS for patients with stage IV at diagnosis was 142 (95%‐CI: 87–not available (NA)) months with 10‐year survival of 50% (95%‐CI: 35%–73%). Conclusion: Patients with VIPoma treated at NET centers have relatively favorable survival, even with distant metastases at diagnosis, although long‐term cure rates remain low.