Natural history of liver metastasis of gastroenteropancreatic neuroendocrine tumors: place for chemoembolization.

Hepatic metastases of gastroenteropancreatic tumors are observed in at least 10% of cases at presentation and in 85% of cases after 20 years of follow-up. They are slow-growing; and there is a 5-year life expectancy that varies between 13% and 60% depending of the degree of differentiation, with occasional survival of more than 20 years. Curative liver resection is the best treatment, with a 4-year survival rate of 73%, but this is possible in only 10% of cases. Chemoembolization is indicated for nonresectable multiple bilobar metastases: 87% of patients respond, half with tumor reduction and the other half with diminution of the symptoms of hypersecretion. The mean survival is 2 years; complete remission of more than 2 years is exceptional. The technique can be repeated but is not without risks, with a possible postembolization syndrome lasting up to 10 days and subsiding spontaneously, without indication for operation. Therefore one lobe only should be embolized at a session. It is not impossible that chemoembolization increases the occurrence of lung metastases. It is only a palliative method but with great functional benefit for patients with hypersecreting tumors.