Recombinant interferon alpha-2b in patients with metastatic apudomas: Effect on tumours and tumour markers

Abstract

Malignant carcinoid tumours, islet cell tumours and medullary carcinomas of the thyroid are tumours with similar clinical features. In patients with unresectable or metastatic tumours leukocyte interferon (IFN) and recombinant human (rh) IFN have demonstrated efficacy. Twenty-four evaluable patients with progressive tumours were treated with 2. 5 megaunits rh IFN a-2b, administered once daily subcutaneously, for a median duration of 7 months (range 0. 5-37 +). Two carcinoid patients demonstrated a response in tumour size, 80% showed stable disease (SD). Sixty percent of the carcinoid patients with elevated urinary 5-hydroxyindoleacetic (5-HIAA) levels reached a biochemical partial response of the urinary 5-HIAA levels (median duration 13. 5 months). In the patients with an islet cell or medullary tumour and an elevated tumour marker, the marker did not further increase. Of the 12 carcinoid patients evaluable for a symptomatic response, ten (83%) experienced a relieve of symptoms. IFN a-2b dose reduction or discontinuation due to toxicity was necessary in three and ten patients, respectively. No neutralising IFN a-2b antibodies developed despite prolonged treatment. In conclusion, IFN a-2b had a beneficial effect in patients with progressive tumours, while long-term IFN a-2b treatment did not augment neutralising antibodies. In view of the IFN a-2b-related toxicity, administration of IFN a-2b on alternating days may be preferable. © 1992 Macmillan Press Ltd.