Hepatic arterial chemoembolization in the management of advanced digestive endocrine tumors

The management of advanced digestive endocrine tumors is often challenging. Liver metastases are usually diffuse at the time of diagnosis, and surgical resection is rarely feasible. Objective response rates with systemic chemotherapy are disappointing. Arterial hypervascularization of most liver metastases from digestive endocrine tumors argues in favor of hepatic arterial chemoembolization (HACE). It is assumed that embolization-induced ischemia sensitizes tumor cells to cytotoxic drugs, whose tumor concentrations are increased by blood flow slowing down. The aims of HACE are: (1) to control otherwise untractable hormone-related symptoms, particularly the carcinoid syndrome (>50% urinary 5-HIAA decrease: 57-91%) and insulinoma-related life-threatening hypoglycemias; (2) to inhibit tumor growth (objective response rates: 33-80%; mean duration: 6-42.5 months), and (3) to improve patients' survival. The postembolization syndrome, usually mild and transient, is the commonest side effect. Major extrahepatic complications are rare. In conclusion, HACE seems to be an attractive alternative treatment for diffuse (unresectable) and progressive metastases confined to the liver in patients with digestive endocrine tumors, mainly following unsuccessful systemic chemotherapy. Further studies assessing the long-term results of HACE and comparing it to other treatments, particularly systemic chemotherapy, are needed.