The clinical characteristics and survival associations of pancreatic neuroendocrine tumors: does age matter?

Background: Pancreatic neuroendocrine tumor (pNET) is the second most common epithelial neoplasm of the pancreas. As in pancreatic adenocarcinoma (PDAC), patients with different onset ages display different clinical features and prognosis. We grouped pNET patients into the early-onset pNET (EOpNET) and typical age-at-onset pNET (TOpNET) to investigate the effect of onset age on their clinical characteristics and prognosis. Methods: Data were collected retrospectively from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2015; cohort 1) and the Fudan University Shanghai Cancer Center (FUSCC) (2005-2018; cohort 2). The clinical characteristics were compared using chi-squared tests. Cox proportional hazards regression was used to evaluate hazard ratios (HRs) and 95% confidence intervals (CIs), and overall survival was formulated by Kaplan-Meier curves. Results: In total, data from 5,368 and 330 patients were included from the SEER database and the FUSCC, respectively. Gender did not affect survival in the EOpNET group. Tumors located in the tail (HR: 0.721, 95% CI: 0.63-0.83, P<0.001) and body (HR: 0.712, 95% CI: 0.60-0.85, P=0.001) had a lower risk of death compared to tumors in the head of the pancreas in the TOpNET group. The overall survival of the EOpNET group {136 [3-143] months} was better than the TOpNET group {85 [3-143] months} (P<0.001) in the SEER database. Results from the FUSCC group were similar to the SEER cohort. Conclusions: The EOpNET group had significantly better overall survival than the TOpNET group, and early surgical resection is encouraged for all pNET patients. In any future personalized treatment of pNET, the patient's onset age should be considered as an important factor in guiding treatment and prognosis.