Nineteen patients with histologically verified midgut
carcinoid tumours and liver
metastases were included in a prospective study with daily recombinant human alpha 2b
interferon injections of 5 million IU subcutaneously for 1 year. All had as much as possible of the primary tumour removed at
laparotomy. Whenever technically possible (in seven cases), an embolization of the hepatic arteries was performed before
interferon start. The response rate of the combined embolization and
interferon treatment (n = 7) was 86% after 1 year, as judged from either a 50% reduction in excretion of
5-hydroxy-3-indoleacetic acid in the urine or a 50% reduction in the area of the largest liver
metastasis as evaluated by computed tomography. All patients experienced an improvement in diarrhoea and/or
flushing. When
interferon was given alone (n = 12), 40% responded on the basis of objective criteria (50% after 6 months), whereas an improvement in either diarrhoea or
flushing was experienced by 70% (75% after 6 months). In this group one patient had died and one had decided to withdraw after 6 months, at which time both were responders. We conclude that
interferon seems to be an effective treatment of malignant metastatic midgut
carcinoid tumours and that embolization of the liver arteries seems to increase the response rate, as judged after 1 year.