BACKGROUND: Early-Onset (EO) pancreatic neuroendocrine tumor (PanNET) is a rare disease but whether is clinically different from late-onset (LO) PanNET is unknown. Our study aimed to evaluate clinical differences and disease outcomes between EO- and LO-PanNET and to compare sporadic EO-PanNET with those with a hereditary syndrome (HS). METHODS: Patients with localized PanNET who underwent pancreatectomy at Memorial Sloan Kettering between 2000-17 were identified. Those with metastatic disease and poorly differentiated tumors were excluded. EO-PanNET was defined as <50 and LO-PanNET >50 years of age at the time of diagnosis. Family history, and clinical and pathology characteristics were recorded. RESULTS: Overall 383 patients were included, 107 (27.9%) with EO-PanNET. Compared with LO-PanNET, EO-PanNET were more likely to have a hereditary syndrome (2.2% vs. 16%, P<0.001) but had similar pathology features such as tumor grade (P=0.6), size (2.2 Vs. 2.3 cm, P=0.5) and stage of disease (P=0.8). Among patients with EO-PanNET those with HS had more frequently a multifocal disease (65% vs. 3.3%, P<0.001). With a median follow-up of 70 months (range 0-238), the 5-year cumulative incidence of recurrence after curative surgery was 19% (95%CI 12-28%) and 17% (95%CI 13-23%), in EO- and LO-PanNET (P=0.3). Five-year disease-specific survival was 99% (95%CI 98-100%) with no difference with respect to PanNET onset time (P=0.26). CONCLUSION: In this surgical cohort, we found that EO-PanNET is associated with hereditary syndromes but has pathological characteristics and oncological outcomes similar to LO-PanNET. These findings suggest that patients with EO-PanNET can be managed similarly to those with LO-PanNET.
