Non-functional pancreatic neuroendocrine tumours: emerging trends in incidence and mortality

Our aim was to determine the epidemiology and recent changes in the trends of non-functional pancreatic neuroendocrine tumours (NF-pNETs) at the population level. In addition, we explored the risk factors that are associated with survival duration.

Cases were identified form the Surveillance, Epidemiology, and End Results (SEER) Programme database from 2000 to 2014. Data on incidence and incidence-based (IB) mortality for NF-pNET were obtained from this database. Secular trends in age-adjusted incidence and IB mortality were determined by using the Joinpoint Regression program. Data analyses were performed using chi-square tests, Kaplan-Meier curves and Cox proportional hazards regression.

Overall, 4766 patients diagnosed with NF-pNET with a median age of 59 years were identified through our descriptive criteria. Caucasian patients accounted for the majority of the study population, and the proportion of patients with distant disease significantly decreased during our study period. Overall, there was an increase in incidence and IB mortality for NF-pNET; however, the rate of increase decreased during the recent years. In addition, the incidence trends of NF-pNET located in the pancreatic head significantly increased, and rates fo increase in IB mortality for NF-pNET in the pancreatic tail decreased in recent years. Additionally, the 1-, 5-, and 10-year survival rates were 79.0, 51.8, 38.1%, respectively. Furthermore, patient age, tumour grade, stage at diagnosis, tumour size, tumour site and resection were associated with mortality.

Despite increases in incidence and IB mortality, the rate of change in IB mortality for NF-pNET has decreased in recent years. Survival duration displayed a secular increase during the overall period, and the prognosis and survival duration of patients were closely related to the time of diagnosis, age of the patients and size and location of the tumour. Appropriate treatment adjustments based on tumour stage may thus facilitate improvements in patient outcomes.