Primary chemotherapy with mitoxantrone and prednisone in advanced breast carcinoma. A phase II study.

Thirty-seven evaluable patients with progressive disseminated breast carcinoma were treated with a combination of mitoxantrone 14 mg/m2 i.v. every 3 weeks plus prednisone 20 mg/m2 p.o. daily with a reducing dose over several weeks. Thirteen of 37 patients (35%) achieved an objective response with two complete regressions. The median duration of response was 7 months and the median duration of survival 14 months. The cardiac function of all patients was monitored by serial left ventricular ejection fraction, at rest and after stress, and 3-monthly thereafter. Ten patients showed a deterioration in the ejection fraction after a minimum cumulative dose of 86 mg/m2 (six cycles), but only four developed clinical cardiac failure which was easily reversible after stopping mitoxantrone. Leucopenia was the dose-limiting toxicity. Nausea and/or vomiting were generally mild and transient. Alopecia was minimal. These results confirmed that this combination is effective and well tolerated in the treatment of disseminated breast carcinoma, and cardiotoxicity can be avoided with adequate monitoring of the left ventricular ejection fraction after six cycles of therapy (86 mg/m2).