Treatment of malignant midgut carcinoid with a highly purified human leukocyte alpha-interferon.

Fourteen patients with liver metastases due to midgut carcinoid tumours were treated with a highly purified human leukocyte alpha-interferon (Interferon Alfanative) at a dose of 2-6 x 10(6) IU subcutaneously 5 days a week. In all patients, the primary tumour was removed before alpha-interferon was given. We found that after one year of treatment with alpha-interferon, 4 patients (= 29%) showed objective response (= reduction by more than 50% of urinary excretion of 5-HIAA and/or by more than 50% of tumour area as determined by computed tomography). Four patients (= 29%) showed stable disease. After 2 years of treatment with alpha-interferon, 4 patients (= 29%) showed objective response. During the second year of treatment, 3 patients died due to tumour progression and in 4 patients the treatment was stopped due to adverse effects. Specific adverse effects to alpha-interferon were reported by 11 of the patients (= 79%). We conclude that the one year objective response to alpha-interferon in 14 patients with liver metastases due to midgut carcinoids is 29% and that the frequency of side effects is high.