Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed HER2-overexpressing metastatic breast carcinoma

- Clinically or radiologically measurable or evaluable disease

- Bidimensionally or unidimensionally measurable lesions

- No ascitic, pleural, or pericardial effusions, osteoblastic bone metastases, or
carcinomatous lymphangitis of the lung as only indicator lesion

- No known clinical brain or meningeal involvement

- Hormone receptor status:

- Not specified

PATIENT CHARACTERISTICS:

Age:

- 18 to 70

Sex:

- Female

Menopausal status:

- Not specified

Performance status:

- ECOG 0-1 OR

- SAKK 0-1

Life expectancy:

- At least 12 weeks

Hematopoietic:

- Hemoglobin at least 10 g/dL

- Platelet count at least 100,000/mm^3

- Absolute neutrophil count at least 2,000/mm^3

Hepatic:

- Bilirubin normal

- SGOT and/or SGPT no greater than 2 times upper limit of normal (ULN) (3 times ULN if
proven liver metastases) OR

- No SGOT and/or SGPT greater than 1.5 times ULN if alkaline phosphatase greater than
2.5 times ULN

Renal:

- Creatinine no greater than 1.25 times ULN

Cardiovascular:

- LVEF normal

- No history of atrial ventricular arrhythmia, congestive heart failure, or angina
pectoris, even if medically controlled

- No history of second or third-degree heart blocks

- No uncontrolled hypertension

Other:

- Not pregnant or nursing

- Fertile patients must use effective contraception

- No pre-existing motor or sensory neuropathy grade 2 or greater

- No psychiatric disorder that would preclude informed consent

- No other prior malignancy except curatively treated nonmelanoma skin cancer or
carcinoma in situ of the cervix

- No definite contraindications for use of corticosteroids

- No other concurrent serious illness or medical condition

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Not specified

Chemotherapy:

- Prior adjuvant or neoadjuvant chemotherapy allowed

- No more than 2 prior chemotherapy regimens for metastatic disease

- No prior cumulative dose of doxorubicin greater than 240 mg/m^2

- No prior cumulative dose of epirubicin greater than 360 mg/m^2

- No prior taxanes

Endocrine therapy:

- Prior hormonal therapy as adjuvant treatment or for metastatic disease allowed

- No concurrent corticosteroids unless started more than 6 months prior to study and at
low doses (i.e., no greater than 20 mg methylprednisolone or equivalent)

Radiotherapy:

- Not specified

Surgery:

- Not specified

Other:

- No other concurrent anticancer drugs

- No other concurrent experimental drugs

- No concurrent bisphosphonates unless initiated more than 3 months prior to study

- Chronic use allowed provided bone metastases are not sole indicator lesions