Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically confirmed recurrent or metastatic breast cancer
HER2-neu overexpressing tumor (2+ or 3+) Measurable or evaluable disease If bone disease
only, must have lytic lesions No carcinomatous meningitis or untreated or uncontrolled
brain parenchymal disease Prior brain parenchymal disease allowed if controlled by
appropriate therapy given at least 8 weeks prior to study, and patient is asymptomatic
from CNS disease Hormone receptor status: Not specified

PATIENT CHARACTERISTICS: Age: 18 and over Sex: Female Menopausal status: Not specified
Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: WBC at least
3,000/mm3 Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3
Hepatic: Bilirubin normal Alkaline phosphatase no greater than 2.5 times upper limit of
normal (ULN) SGOT and SGPT no greater than 1.5 times ULN Renal: Creatinine no greater than
2.0 mg/dL Cardiovascular: No congestive heart failure Ejection fraction greater than 45%
by MUGA No myocardial infarction within the past 6 months No ischemic heart disease
requiring medication No uncontrolled hypertension Other: No peripheral neuropathy grade 2
or more No other prior malignancy within the past 5 years except curatively treated basal
cell or squamous cell carcinoma of the skin, carcinoma in situ of the cervix, or
contralateral breast cancer No active unresolved infection No history of hypersensitivity
reaction to products containing Polysorbate 80 No poorly controlled diabetes mellitus Not
pregnant Negative pregnancy test Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent biologic response modifiers
Chemotherapy: Prior adjuvant chemotherapy allowed No more than 1 prior chemotherapy
regimen for metastatic disease No prior taxane (docetaxel or paclitaxel) Prior doxorubicin
allowed if total dose less than 250 mg/m2 No other concurrent chemotherapy Endocrine
therapy: Prior hormonal therapy allowed No concurrent hormonal therapy Radiotherapy: At
least 4 weeks since prior radiotherapy No prior cumulative radiotherapy to more than 25%
of bone marrow No concurrent radiotherapy Surgery: Not specified Other: At least 7 days
since prior antibiotics No other concurrent investigational drugs No other concurrent
antineoplastic therapy No concurrent parenteral antibiotics