Tu1564 Predictors of Lymph Node Metastases and Impact on Survival in Resected Pancreatic Neuroendocrine Tumors, a Single Center Experience

Abstract

BACKGROUND: Staging for pancreatic neuroendocrine tumors (PNET) considers tumor size and lymph node (LN) status; however, correlation with survival remains unclear. METHODS: A single-institution database of patients with resected PNET was analyzed. RESULTS: Of the 150 patients, incidentally discovered PNET was the most common presentation (42%). One hundred thirteen patients (75%) had LN data, 32 (28%) with positive LN (LN1). Procedure and tumor size did not predict LN1. Perineural invasion (P 5 .016) and lymphovascular (P , .001) invasion, however, were more common in LN1. Multivariate analysis showed poor/moderate differentiation predicted LN1. Median follow-up was 52 months and median overall survival was 225 months. Fifty-two patients (35%) developed recurrence and median disease-free survival (DFS) was 74 months. Only poor/moderate differentiation affected DFS. CONCLUSIONS: PNET has an unclear prognosis based on variables factored into stage. In this study, tumor size did not predict LN1; furthermore, LN1 did not impact overall survival or DFS. Tumor differentiation appears to be more important in determining prognosis. Pancreatic neuroendocrine tumors (PNET) are uncommon, with an annual incidence of 2.2 per 1,000,000, based on the 2000 US population data from the Surveillance, Epidemiology, and End Results database, with men