Surgical Management of Advanced Pancreatic Neuroendocrine Tumors: Short-Term and Long-Term Results from an International Multi-institutional Study

Background. The role of extended resections in the management of advanced pancreatic neuroendocrine tumors (PNETs) is not well defined. Methods. Between 1995 and 2012, 134 patients with PNET underwent isolated (isoPNET group: 91 patients) or extended pancreatic resection (synchronous liver metastases and/or adjacent organs) (advPNET group: 43 patients). Results. The associated resections included 27 hepatectomies, 9 vascular resections, 12 colectomies, 10 gastrectomies, 4 nephrectomies, 4 adrenalectomies, and 3 duodenojejunal resections. R0 was achieved in 41 patients (95 %) in the advPNET. The rates of T3-T4 (73 vs 16 %; p<.0001) and N+ (35 vs 13 %; p =.007) were higher in the advPNET group. Mortality (5 vs 2 %) and major morbidity (21 vs 19 %) rates were similar between the 2 groups. The 5-year overall survival (OS) of the series was 87 % in the isoPNET group and 66 % in the advPNET group (p =.006). Only patients with both locally advanced disease and liver metastases showed worse survival (p =.0003). The advPNET group developed recurrence earlier [disease-free survival (DFS) at 5 years: 26 vs 81 %; p<.001]. In univariate analysis, negative prognostic factors of survival were: poor degree of differentiation (p<.001), liver metastasis (p =.011), NE carcinoma (p< . 001), and resection of adjacent organs (p =.013). The multivariate analysis did not highlight any factor that influenced OS. In multivariate analysis independent DFS factors were a poor degree of differentiation (p =.03) and the European Neuroendocrine Tumor Society stage (p =.01). Conclusions. An aggressive surgical approach for locally advanced or metastatic tumors is safe and offers long-term survival.