DISEASE CHARACTERISTICS: Histologically confirmed metastatic adenocarcinoma of the breast Prior treatment with an anthracycline (e.g., doxorubicin or epirubicin) and a taxane (e.g., paclitaxel or docetaxel) either as adjuvant therapy or for advanced disease Bidimensionally measurable disease Sentinel lesions must be outside of any prior radiation port No resected disease or stage IV with no evaluable disease No brain metastases or leptomeningeal disease No symptomatic lymphangitic pulmonary metastases Hormone receptor status: Not specified