Comparative phase II study of idarubicin versus doxorubicin in advanced breast cancer.

The aim of the present study is to confirm the antitumor activity of orally administered idarubicin (IDA) in patients with advanced breast cancer. Doxorubicin (ADRIA) was chosen as control treatment and the patients were randomized to receive either IDA or ADRIA according to a 2:1 ratio. Sixty-three patients, 77% of whom were pretreated with chemotherapy excluding anthracyclines, entered the study. The doses were: IDA 45 mg/m2 orally on 3 consecutive days every 28 days: ADRIA 75 (60) mg/m2 intravenously every 21 days. A complete + partial response (CR + PR) was observed in 11/37 (30%) evaluable cases treated with IDA and in 6/19 (32%) cases treated with ADRIA. If all the patients were included, the CR + PR remission rates were 27.5 and 27%, respectively. There were no significant differences as regards time to remission, duration of remission and survival. None of 10 cases who crossed over the treatments responded to the second therapy. The most frequent side effects of IDA were myelosuppression and nausea/vomiting. The only significant statistical difference between the two anthracyclines was the lower incidence of alopecia after IDA. Although there were 3 cases of cardiotoxicity after ADRIA, 2 of which severe, no case of clinical cardiotoxicity was observed after IDA. The present study confirms that orally administered IDA is an active agent in advanced breast cancer.