Pancreatic neuroendocrine tumors: 12-years experience of Instituto Portugues Oncologia de Lisboa

Introduction: Pancreatic neuroendocrine tumors (PNETs) have a broad spectrum of clinical behavior, histopathological characteristics and prognosis. Hormonal production distinguishes functional from nonfunctional tumours. The aim was to review the cases of PNETs diagnosed and/or followed, between 2000 and 2011, at Instituto Portugues de Oncologia de Lisboa, Francisco Gentil (IPOLFG). Methods: Data of clinical files of PNETs of the IPOLFG was analysed. Patients were identified through South Regional Cancer Registry and databases of IPOLFG's Pathology and Endocrinology Departments. Results: 44 PNETs were identified, 68.2% nonfunctioning and 31.8% functioning (11 insulinomas and 3 gastrinomas). 52.3% of the cases were male. The median age at diagnosis was 55 years (range 3183). The majority of all PNETs was symptomatic (79.5%), unifocal (70.5%) and well-differentiated (63.6%). Loco-regional disease and metastases were present in 61.4% and 56.8% of the cases, respectively. Magnetic resonance and endoscopic ultrasonography were the most sensitive exams. Surgery was the main treatment offered. Median follow-up time was 32 months (+/- 35; range 1 to 130 months) and median survival was 85 months (+/- 11). Comparison between nonfunctioning and functioning PNETs, revealed that patients in the former group were less symptomatic (73.3 vs 92.9%), presented more often loco-regional disease (73.3 vs 35.7%), metastases (70.0 vs 28.6%), higher proliferative indexes and tumoural diameter (5.4 vs 2.9 cm). Median survival was higher in functioning tumors (106 vs 72 months). Factors associated with a more favorable prognosis were: hormonal secretion; histological differentiation; absence of angioinvasion; absence of locorregional disease or metastization; low proliferative indexes. Conclusion: As observed in other series, the majority of PNETs were nonfunctional and the prognosis of these cases was worse than the prognosis of functional tumours. (C) 2012 Sociedade Portuguesa de Endocrinologia, Diabetes e Metabolismo. Published by Elsevier Espana, S.L. All rights reserved.