Evaluation of the current treatment strategies for poorly differentiated pancreatic neuroendocrine tumors

Abstract

Presenter: Jamie Glasser MS | Sarasota Memorial Cancer Institute Background: The management of pancreatic neuroendocrine tumors (PNET) varies between observation (O), pancreatic resection (PR) and enucleation (E). Currently, size, grade and location are used to determine which treatment strategy may be employed. We sought to evaluate each strategy and further clarify the role for surgery with regards to patients with poorly differentiated (PD) PNET. Methods: Utilizing the National Cancer Database we identified patients with poorly differentiated pancreatic neuroendocrine tumors and stratified based upon size and management. Mann-Whitney U and Kruskal were used to compare continuous variables and Pearson’s Chi-square test was used to compare categorical variables. Unadjusted survival analyses were performed using the Kaplan-Meier method. Multivariate analysis (MVA) was performed to identify predictors of survival. All statistical tests were two-sided and p<0.05 was considered significant. Results: We identified 3,187 patients with PD PNET with a median age of 61 (18-90). There were 84 (2.6%) patients with tumors 2 cm. There were more males than females p2cm demonstrated a higher incidence of node positivity compared to other cohorts, p2cm, p=0.01. Patients with tumors 2cm tumors, 5-year survival was 65% in those undergoing surgery vs 16% in those who did not, p<0.001. There was no difference in survival in those patients undergoing pancreatic enucleation vs those undergoing pancreatic resection, (median survival 102.2 months PR, vs 107.9 months PE, p=0.16). Multivariate analysis revealed age, tumor location, size, surgery, and clinical stage were predictors of survival. Conclusion: Poorly differentiated pancreatic neuroendocrine tumors exhibit high incidence of node positivity, even in patients with tumors < 1cm. Surgery improves survival in all patients with poorly differentiated PNET. Thus, observation has no role in the management of PD PNET.