Treatment of malignant metastatic midgut carcinoid tumours with recombinant human alpha2b interferon with or without prior hepatic artery embolization.

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.