Local treatment for focal progression in metastatic neuroendocrine tumors

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. 26% 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.