Anatomic site as prognostic marker of pancreatic neuroendocrine tumors: a cohort study

Patients with pancreatic neuroendocrine tumors (PNET) have variable prognosis, even with comparable tumor grade and stage. In the current study we aimed to evaluate the prognostic utility of the intrapancreatic PNET anatomical site.

Cohort study based on the Surveillance Epidemiology and End Results database.

Patients diagnosed with non-functioning PNET between 2004 and 2015 were compared by anatomic site for disease-specific mortality and all-cause mortality, using log-rank test and by multivariable cox regression analysis.

Overall, 4171 patients (1839 women (44.1%), median age strata 60-64 years, range 10-14 to ≥85 years) were included in our analysis. Patients with PNETs located at the head vs body/tail of the pancreas had comparable tumor diameter, as well as ethnicity, gender and age distributions, but had higher rates of grade III and IV NET (13.2 vs 6.6% and 4.4 vs 1.9%, respectively, P < 0.001). NETs located at the head vs body/tail of pancreas were more likely to be locally advanced (32.2 vs 19.9%) with no difference in distant metastases (36.4 vs 33.5%, respectively, P < 0.001). Patients with NETs of the head vs. body/tail of the pancreas had higher disease-specific mortality risk in univariate (log-rank test, P < 0.001) and multivariable analysis (hazard ratio (HR): 1.34, 95% confidence interval: 1.10-1.65, P = 0.004). Multivariable analysis for all-cause mortality also showed increased risk for patients with pancreatic head vs. body/tail PNET (HR: 1.23, P = 0.013).

PNET anatomical location is associated with the mortality risk and should be considered as a prognostic factor, and as an additional consideration in directing patients management.