Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically confirmed metastatic breast cancer that has
demonstrated at least partial response to any salvage regimen Partial response defined as
at least 50% reduction in measurable or evaluable disease for at least 4 weeks, no disease
progression, no new lesions, or bone lesions that remain static for at least 8 weeks with
an improvement in pain symptoms No more than 3 organs involved with metastatic disease No
prior or active CNS involvement Hormone receptor status: Not specified

PATIENT CHARACTERISTICS: Age: 18 to 64 Sex: Female Menopausal status: Not specified
Performance status: ECOG 0-1 Life expectancy: Not specified Hematopoietic: Not specified
Hepatic: Bilirubin no greater than 2.0 mg/dL SGOT or SGPT no greater than 2.5 times upper
limit of normal No history of severe hepatic dysfunction Renal: Creatinine no greater than
2.0 mg/dL OR Creatinine clearance at least 60 mL/min Cardiovascular: No severe cardiac
dysfunction Ejection fraction at least 50% by MUGA No major heart disease Controlled
hypertension allowed Pulmonary: DLCO at least 50% of normal OR No symptomatic obstructive
or restrictive disease Other: Not pregnant or nursing Negative pregnancy test Fertile
patients must use effective barrier contraception No uncontrolled insulin dependent
diabetes mellitus No uncompensated major thyroid or adrenal dysfunction No significant
skin breakdown from tumor or other disease No other prior malignancy in past 5 years
except nonmelanoma skin cancer or carcinoma in situ of the cervix No active infections HIV
negative

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: See Disease
Characteristics No more than 2 prior salvage regimens for metastatic disease No prior
topotecan Endocrine therapy: Not specified Radiotherapy: Not specified Surgery: Not
specified Other: No concurrent nitroglycerin preparations for angina No concurrent
antiarrhythmics for major ventricular arrhythmias