DISEASE CHARACTERISTICS:

• Histologically confirmed metastatic breast cancer
• At least 1 line of prior chemotherapy for metastatic disease (adjuvant or neoadjuvant chemotherapy is considered first line if completed less than one year prior to palliative chemotherapy)
• No cerebral metastases

• Hormonal receptor status:

  • Not specified

PATIENT CHARACTERISTICS:

Age:

• Not specified

Sex:

• Female

Menopausal status:

• Not specified

Performance status:

• WHO 0-2

Life expectancy:

• Not specified

Hematopoietic:

• Absolute neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm ^3

Hepatic:

• Bilirubin no greater than 2.5 times upper limit of normal (ULN)
• AST/ALT no greater than 2.5 times ULN

Renal:

• Creatinine no greater than 1.58 mg/dL

Cardiovascular:

• No clinically significant cardiac insufficiency or ischemic disease

Pulmonary:

• No bronchoconstriction other than pulmonary lymphangitis

Other:

• No serious chronic disease
• No bowel obstruction
• Not pregnant or nursing

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No concurrent immunotherapy
• No concurrent prophylactic growth factor

Chemotherapy:

• See Disease Characteristics
• At least 4 weeks since prior chemotherapy
• No prior high-dose chemotherapy
• No other concurrent chemotherapy

Endocrine therapy:

• No concurrent hormonal therapy
• No concurrent steroid therapy except in an emergency

Radiotherapy:

• At least 4 weeks since prior radiotherapy (for primary tumor or axillary or mammary chain treatment only)
• No concurrent radiotherapy

Surgery:

• Not specified

Other:

• No other concurrent antitumor therapy