In most cases, liver metastases are not completely resectable. Cytoreductive surgery, with or without radiofrequency ablation or cryoablation, has been used to palliate symptoms. A systematic review found no randomized or quasi-randomized trials comparing cytoreductive surgery to other palliative approaches such as chemotherapy or tumor product inhibitors. The evidence for surgical cytoreduction of unresectable liver metastases is restricted to case series [Level of evidence: 3iiD or 3iiiD], and interpretation of outcomes may be strongly affected by patient selection factors.
Systemic Therapy for Advanced and Metastatic Disease
Somatostatin analogs may be effective in reducing the symptoms of functional tumors.
Chemotherapy using drugs such as the following, either alone or in combination, has been shown to have antitumor effects, but evidence is weak or conflicting regarding the impact of chemotherapy on overall survival:[15,16,17]
More recently, a variety of systemic agents have shown biologic or palliative activity, including:[5,18]
- Tyrosine kinase inhibitors (e.g., sunitinib).
- Vascular endothelial growth factor pathway inhibitors.
- Mammalian target of rapamycin inhibitors (e.g., everolimus).
Nearly all of the evidence of activity derives from case series.[Level of evidence 3iiiDiv] However, there are ongoing placebo-controlled randomized trials of everolimus  and sunitinib  that have been reported in abstract form showing an increase in progression-free survival in each case.[Level of evidence 1iDiii]
Favorable responses have been reported in patients with advanced progressive pancreatic NETs after treatment with several radiolabeled somatostatin analogs in which the analogs octreotide, octreotate, lanreotide, or edotreotide are stably attached to the radionuclides 111Indium, 90Ytrium, or 177Lutrium.[21,22,23] The relative efficacy of these various compounds is unknown. Study designs have been limited to case series with tumor response, biochemical response, or symptom control as the measure of efficacy.[Level of evidence 3iiiDiv]
As noted in each of the clinical situations, there is a paucity or absence of high-level evidence, and a need for randomized controlled trials.
Current Clinical Trials
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with islet cell carcinoma. The list of clinical trials can be further narrowed by location, drug, intervention, and other criteria.