Combination chemotherapy with oral idarubicin and cyclophosphamide for metastatic breast cancer.
A group of 40 women with objectively measurable metastatic breast cancer was treated with idarubicin, 35 mg/m2 on day 1, and cyclophosphamide, 200 mg/m2 on days 2-5, both drugs being administered orally every 3 weeks. Of 37 evaluable patients, 4 (10.8%) achieved a complete response and 14 (37.8%) a partial response, for an overall response rate of 48.6% (95% confidence interval, 37.45%-59.75%). In previously untreated patients the response rate was 58.3%, whereas it was 44% in patients previously exposed to cytotoxic drugs. The median duration of response was 6.5 months, and the median survival of all patients was 10.5 months. Moderate nausea and vomiting were common. Diarrhoea, which occurred in 37% of the patients, was usually short-lived. Alopecia was generally mild, myelosuppression was the dose-limiting toxicity. Grade 3-4 leukopenia occurred only in pretreated patients. In previously untreated patients it was generally of grade 1-2. Laboratory evidence of cardiotoxicity (greater than or equal to 20% decrease in the left-ventricular ejection fraction from the baseline value) was observed in 3 out of 26 patients, who had at least two determinations of the left-ventricular ejection fraction, and was transient in nature. No cases of congestive heart failure were observed. These results indicate that the combination of idarubicin + cyclophosphamide represents a practical and effective regimen to be used in selected patients with advanced breast cancer.