Longterm outcome of rare functioning pancreatic neuroendocrine neoplasms

Abstract

Abstract Introduction: Rare functional pancreatic neuroendocrine neoplasms (rf-pNENs), such as VIPomas, calcitoninomas and glucagonomas are extremely rare tumors. Thus, their characteristics and long-term prognosis have not yet been well defined. Methods:Clinicopathological characteristics, including preoperative diagnostics, surgical procedures, other treatments and long-term outcome of patients with rf-pNEN operated in the ENETS Center of Excellence Marburg were retrospectively analyzed. Results: Between 2002 and 2022, 12 of 216 (5,5%) patients with pNEN had rf-pNEN, including three VIPomas, four glucagonomas and five calcitoninomas. Among these 5 were women and 7 were men with a median age of 60 (range 28-73) years at the time of the first surgery. The tumor was visualized by preoperative imaging in all 12 patients, and six patients had distant metastases at the time of diagnosis. The tumor was located in the pancreatic tail in 9 patients and the median tumor size was 82 (range 12-220) mm. Eleven patients underwent tumor resections (2 robotic, 9 conventional), and 9 of these 11 patients received R0 resections. After a median follow-up of 75 (range 1-247) months, six patients were alive, five of whom had no evidence of disease. All patients who remained disease-free had an initial R0 resection of the primary tumor and no initial liver involvement. Conclusion: rf-pNENs are a heterogeneous group of tumors with a good long-term prognosis, if detected early and initially radically resected. Long-term survival, however, can be also achieved in patients with metastasized tumors using multimodal treatment.