Recombinant interferon in advanced breast cancer.

Fifteen patients with locally advanced refractory breast cancer have been treated with recombinant leucocyte interferon ( rIFN -alpha A) for up to 12 weeks. Toxicity was considerable with the initial dosage schedule employed but became acceptable after reducing the starting dose by 50%. Minor side effects occurred in all patients and major CNS toxicity in six. Nine patients showed some evidence of tumour regression at 4 weeks. Only two of these were still responding at 12 weeks. Response was unrelated to the length of previous history, oestrogen receptor status or previous responsiveness to cytotoxic or hormone therapy.