Treatment of metastatic pancreatic neuroendocrine tumors: Relevance of ENETS 2016 guidelines

The choice of first-line treatment for metastatic pancreatic neuroendocrine tumors (mP-NET) is mainly based on prognostic factors. ENETS-2016 guidelines stratified treatment according to 3 groups: Group 1, patients in whom all lesions could be removed; Group 2, patients with Ki67 <10%, low tumor burden, no symptoms and stable disease, for whom a watch-and-wait strategy or somatostatin analogs are proposed; Group 3, symptomatic patients or with Ki67 >10% or significant tumor burden or progressive disease, for whom a systemic chemotherapy is proposed. This retrospective study aimed to determine patient distribution, characteristics and outcome among these 3 groups. Patients with mP-NET diagnosis from 2004 to 2016 were categorized into the three groups. Prognosis was calculated using the Kaplan-Meier method. All treatments were recorded, and consistency with ENETS guidelines was explored. 104 patients were analyzed: 64% synchronous mP-NET, 80% grade 2 tumors and median overall survival (OS) of 104 (95% CI: 65-143) months. There were 15 patients in ENETS Group 1, 16 in Group 2 and 73 in Group 3. Median OS was not reached in Groups 1 and 2 and was 64 months (35-93) in Group 3. High liver tumor volume, high-grade tumor and progressive disease were associated with worse OS in multivariate analysis. The first-line treatment was in accordance with guidelines in 82%. 77% percent of deceased patients received less than 4 lines of treatment. Most patients are in Group 3 and do not receive all available treatments. Thus, trials are warranted to improve first-line chemotherapy. Alternative treatments may be considered for less aggressive disease.