Predictors of lymph node metastases and impact on survival in resected pancreatic neuroendocrine tumors: a single-center experience

BackgroundStaging for pancreatic neuroendocrine tumors (PNET) considers tumor size and lymph node (LN) status; however, correlation with survival remains unclear.MethodsA single-institution database of patients with resected PNET was analyzed.ResultsOf 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 (LN+). Procedure and tumor size did not predict LN+. Perineural invasion (P = .016) and lymphovascular (P < .001) invasion, however, were more common in LN+. Multivariate analysis showed poor/moderate differentiation predicted LN+. 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.ConclusionsPNET has an unclear prognosis based on variables factored into stage. In this study, tumor size did not predict LN+; furthermore, LN+ did not impact overall survival or DFS. Tumor differentiation appears to be more important in determining prognosis.