Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically proven breast cancer

- Metastatic disease OR

- Locoregional relapse following optimal adjuvant therapy and regional treatment

- HER-2/neu overexpression (3+ by immunohistochemistry OR gene amplification by
FISH)

- 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:

- Absolute neutrophil count at least 1,500/mm3

- Platelet count at least 100,000/mm3

- Hemoglobin at least 10 g/dL

Hepatic:

- SGOT and SGPT no greater than 3 times upper limit of normal (ULN)

- Alkaline phosphatase no greater than 2 times ULN unless documented to be arising from
bone

- Bilirubin no greater than 1.5 times ULN

Renal:

- BUN less than 1.5 times ULN

- Creatinine less than 1.5 times ULN

Cardiovascular:

- LVEF normal by radioisotope method

- No history of congestive cardiac failure, myocardial infarction, cardiac arrhythmia,
or ischemic heart disease requiring medication

Other:

- Not pregnant or nursing

- Fertile patients must use effective contraception

- No known sensitivity to benzyl alcohol

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

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

Biologic therapy:

- Not specified

Chemotherapy:

- No prior doxorubicin greater than 240 mg/m2

Endocrine therapy:

- Not specified

Radiotherapy:

- Prior radiotherapy to left breast or chest wall allowed

Surgery:

- Not specified