PRIOR CONCURRENT THERAPY: Biologic therapy: At least 3 weeks since prior immunotherapy No prior bone marrow transplantation Chemotherapy: Prior nonanthracycline based chemotherapy for breast cancer allowed No prior anthracycline based chemotherapy for metastatic disease Prior anthracycline based adjuvant chemotherapy allowed if: At least 6 months have elapsed from completion of adjuvant therapy until the detection of metastatic disease Cumulative dose no greater than 300 mg/m2 Endocrine therapy: At least 3 weeks since prior hormonal therapy No concurrent hormonal or corticosteroid therapy for breast cancer Radiotherapy: At least 2 weeks since prior radiotherapy and recovered No concurrent radiotherapy Surgery: Not specified