Tolerance to long-term treatment of malignant midgut carcinoid with a highly purified human leukocyte alpha-interferon.

We report here the long-term toleration of treatment with a highly purified human leukocyte alpha-interferon (Interferon Alfanative) in patients with midgut carcinoid tumours with liver metastases. During an 18-month period, 13 consecutive patients with this diagnosis commenced treatment with a-interferon. Five patients died during the first 2 years of treatment due to tumour progression, and in 2 patients the treatment with a-interferon had to be stopped due to severe adverse effects (mainly joint pain and tiredness). Hence, 6 patients tolerated the treatment for a long-term period (greater than 2 years), and in these patients the treatment has continued for more than 3 years; in 3 of them for more than 4 years. In these 6 patients, adverse effects of mild or moderate degree have been observed in 2 patients: itching and hair loss in one and joint pain and hair loss in another. Except for a significant reduction in the blood number of WBC and thrombocytes (although in no patient did leukocytopenia or thrombocytopenia develop) and the development of hypothyroidism in one patient, no biochemical tests have shown significant changes during the long-term treatment. In these 6 patients, objective tumour regression has been observed in 2 patients, stable disease in 3 patients and progression in 1 patient. We conclude that, of the patients initiated on treatment with a-interferon for midgut carcinoids with liver metastases, only approximately 50% are still on the treatment after 2 years. These patients, on the other hand, may continue for a longer period of time with a low degree of adverse effects.