PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior total dose of doxorubicin or daunorubicin greater than 450 mg/m2 No prior topotecan or any other topoisomerase I inhibitor, etoposide, etoposide phosphate, or teniposide Endocrine therapy: Not specified Radiotherapy: Not specified Surgery: Not specified Other: No concurrent nitroglycerin preparations for angina pectoris No concurrent antiarrhythmic drugs for major ventricular dysrhythmias