DISEASE CHARACTERISTICS: Histologically confirmed refractory metastatic breast cancer Must have either relapsed or failed to achieve complete remission after combination chemotherapy with or without stem cell or marrow transplantation No CNS disease No generalized or total mass liver involvement greater than 25% volume No pulmonary metastasis involving greater than 25% of lung volume Tumor markers and evidence of metastatic disease by physical exam or radiography required for patients with bone disease only Hormone receptor status: Not specified