The Landmark Series: Neuroendocrine Tumor Liver Metastases

Abstract

Background: Neuroendocrine tumors are becoming increasingly prevalent, with many patients presenting with or developing metastatic disease to the liver.

Methods: In this landmark series paper, we highlight the critical studies that have defined the surgical management of neuroendocrine tumor liver metastases, as well as several randomized control trials which have investigated strategies for systemic control of metastatic disease.

Results: Liver-directed surgical approaches and locally ablative procedures are recommended for patients with limited, resectable, and in some cases, nonresectable tumor burden. Angiographic liver-directed techniques, such as transarterial embolization, chemoembolization, and radioembolization, offer another approach for management in patients with liver-predominant disease. Peptide receptor radionuclide therapy is a promising therapy for patients with hepatic and/or extrahepatic metastases. Various systemic medical therapies are also available as adjunct or definitive therapy for patients with metastatic disease.

Conclusions: This article reviews current data regarding management of neuroendocrine liver metastases and highlights areas for future study.

Keywords: Liver debulking; Liver metastases; Neuroendocrine; PRRT.

Figure 1:

Kaplan-Meier survival stratified by margin status (R0/R1 vs. R2) after first liver directed operation and hormonal function of the NET. Patients with hormonally functioning tumors who had R0/R1 resection had greater survival than other groups (P = 0.008; reprinted from Mayo et al. with permission).

Figure 2:

Kaplan-Meier curves for (A) Overall survival and (B) Progression free survival stratified by the amount of tumor debulked. There was a difference in (A) OS comparing <70% to 70%–90% (P < .01) but not 70%–90% to >90% (P = .6). There was a significant difference in (B) PFS comparing <70% to 70%–90% (P < .01) and 70%–90% to >90% (P < .01; reprinted from Scott et al. with permission).