New systemic treatments have improved the therapeutic landscape for patients with metastatic gastroenteropancreatic neuroendocrine tumors (GEP-NETs). While drugs such as everolimus, sunitinib, temozolomide and 177Lutetium-dotatate are appropriate for patients with widespread disease progression, local treatment approaches may be more appropriate for patients with unifocal progression. Surgical resection, radiofrequency ablation (RFA), hepatic arterial embolization (HAE) or radiation, can control discrete sites of progression, allowing patients to continue their existing therapy and sparing them toxicities of a new systemic treatment. We identified 69 patients with metastatic GEP-NETs who underwent a local treatment for focal progression in the setting of widespread metastases. Twenty-six percent underwent resection, 27% RFA, 23% external beam radiation and 23% selective HAE. With a median follow-up of 25 months, 42 (61%) patients subsequently progressed to the point of requiring additional intervention (12 locoregional, 30 systemic) for disease control. Median time to new systemic treatment was 32 months (95% CI, 16.5–47.5 months). Median time to any additional intervention was 19 months (95% CI, 8.7–25.3 months). Control of local sites of progression enabled the majority of patients to remain on their existing systemic treatment and avoid potential toxicities associated with salvage systemic therapy.
Taymeyah Al-Toubah, Stefano Partelli, Mauro Cives, Valentina Andreasi, Franco Silvestris, Massimo Falconi, Daniel A Anaya and Jonathan Strosberg
Claudio Ricci, Stefano Partelli, Carlo Ingaldi, Valentina Andreasi, Davide Campana, Francesca Muffatti, Laura Alberici, Cecilia Giorgi, Riccardo Casadei and Massimo Falconi
Overall survival (OS) is considered as the standard measure of outcome in oncology. However, considering that resectable pancreatic neuroendocrine neoplasms (Pan-NENs) usually have a long OS, the feasibility of prospective studies is questionable due to a long follow-up period needed. The primary endpoint was to validate the use of disease-free survival (DFS) as a surrogate measure of OS. The secondary endpoint was to calculate the gain in sample size using DFS instead of OS in hypothetical prospective studies with two parallel groups. A systematic review of studies reporting both OS and DFS in resected Pan-NENs was carried out. Multivariate linear regression analysis was used to evaluate if DFS predicts the OS in patients undergoing radical resection. Monte Carlo simulation was performed to estimate the gain in sample size, supposing the use of DFS instead of OS, to evaluate a hypothetical adjuvant treatment after surgery in a randomized trial. Six studies reporting data about seven cohorts of resected Pan-NENs were included, for a total of 1088 patients. The median OS and DFS were 144 (27–134) and 122 (50–267) months, respectively. There was a significant correlation between DFS and OS (R 2 = 0.988; P = 0.035). Monte Carlo simulations showed that the number of patients needed to demonstrate a significant reduction of probability of a ‘target event’ in a hypothetical two-arm group exploring the hypothetical role of adjuvant therapy was reduced using DFS instead OS. This finding supports the legitimacy of using DFS as an acceptable surrogate for OS in surgical clinical trials.