Ablative therapies for liver metastases of digestive endocrine tumours.

Hepatic metastases are frequently encountered in patients with digestive endocrine tumors and their presence plays an important role in quality of life and overall prognosis. Surgery is the treatment method of choice for hepatic metastases but this is frequently impossible due to the extent of disease. Systemic chemotherapy is offered to patients with diffuse and/or progressive liver metastases but results are disappointing especially in patients with metastases of midgut origin. In the latter patients with carcinoid syndrome, somatostatin analogs are frequently initially effective but their efficacy wanes due to disease progression and development of tachyphylaxis. Other therapeutic options in the treatment of hepatic metastases are locoregional strategies where vascular occlusion induces ischemia in these highly vascular tumors using either surgical or radiological techniques. Available methods include surgical ligation of the hepatic artery, transient hepatic ischemia or sequential hepatic arterialization. Trans-catheter arterial chemoembolization has proven effective in terms of long palliation and objective tumor responses. Other treatments aimed at regional destruction either alone or in combination with surgery include radiofrequency ablation and cryotherapy. The latter are usually important adjuncts to surgery and are usually reserved for limited disease.