Objectives: Currently, no reasonable staging system exists for pancreatic neuroendocrine tumors (PNET) to guide treating physicians. The aim of this study was to devise a staging system of relevant prognostic factors to better predict overall survival in PNET.
Methods: A prospective 300 patient cohort and a review of the Surveillance Epidemiology and End Results database identified 6,447 patients with PNET from 1973 to 2008. Significant prognostic factors were created for an initial. Tumor: T (T1: ≤3 cm and localized to pancreas, T2: >3 cm and localized to the pancreas; T3: extension to adjacent organs and vessels), grade: G (G1: well/moderate and G2: poor/undifferentiated), and metastasis: M (M0: no distant mets, M1: distant mets) staging system.
Results: Significant predictors of survival on multivariate analysis included age, size, grade, and metastasis. Based on the TGM staging system: stage 1 (T1-2, G1, M0), stage 2 (T1-2, G2, M0), stage 3 (T3G2M0, Tany, G1, M1), stage 4: (Tany, G2, M1) was created with survival being statistically different between stages (p < 0.0001). Median survival rates were stage 1, 55 months; stage 2, 50 months; stage 3, 46 months; and stage 4, 25 months.
Conclusions: Incorporation of this newly developed staging system into clinical practice will improve the ability to predict prognosis and aid in stratification of patients for clinical trials.