Liver metastases of neuroendocrine tumours; early reduction of tumour load to improve life expectancy

Abstract

Background: Neuroendocrine tumours frequently metastasize to the liver. Although generally slowly progressing, hepatic metastases are the major cause of carcinoid syndrome and ultimately lead to liver dysfunction, cardiac insufficiency and finally death.

Methods: A literature review was performed to define the optimal treatment strategy and work-up in patients with neuroendocrine hepatic metastases. Based on this, an algorithm for the management of these patients was established.

Results: Platelet serotonin and chromogranin A are useful biomarkers for detection and follow-up of neuroendocrine tumour. Helical computed tomography and somatostatin receptor scintigraphy are the most sensitive diagnostic modalities. Surgical debulking is an accepted approach for reducing hormonal symptoms and to establish better conditions for medical treatment, but is frequently impossible due to the extent of disease. A novel approach is the local ablation of tumour by thermal coagulation using therapies such as radiofrequency ablation (RFA) or laser induced thermotherapy (LITT). These techniques preserve normal liver tissue. There is a tendency to destroy metastases early in the course of disease, thereby postponing or eliminating the surgically untreatable stage. This can be combined with postoperative radioactive octreotide to eliminate small multiple metastases. In patients with extensive metastases who are not suitable for local destruction, systemic therapy by octreotide, 131I-MIBG treatment or targeted chemo- and radiotherapy should be attempted. A final option for selective patients is orthotopic liver transplantation.

Conclusion: Treatment for patients with neuroendocrine hepatic metastases must be tailored for each individual patient. When local ablative therapies are used early in the course of the disease, the occurrence of carcinoid syndrome with end stage hepatic disease can be postponed or prevented.

Figure 1

CT scan of the liver of a 34-year old man with metastases of a neuroendocrine tumour of the pancreas. Before LITT the CT scan shows a metastases of 4.7 cm in diameter in segment VII and a second metastases of 2.0 cm in diameter in segment VII subcapsular (not visible) of the liver (figure 2A). Control CT scan one week after LITT showing a coagulation lesion in segment VII of 9.0 cm in diameter and subcapsular in segment VII of 4.8 cm in diameter (figure 2B).

Figure 2

Protocol for management of patients with neuroendocrine hepatic metastases. CT, computed tomography; MRI, magnetic resonance imaging; SRS, somatostatin receptor scintigraphy; RFA, radiofrequency ablation; LITT, laser induced thermotherapy; ¹³¹I-MIBG, Iodine-131 metaiodobenzylguanidine.