Biological Therapy in Treating Women With Stage IV Breast Cancer

DISEASE CHARACTERISTICS:

Phase I:

Histologically confirmed infiltrating ductal carcinoma of the breast

Metastatic disease

Clinically asymptomatic with non-life-threatening metastases allowed

Measurable or evaluable disease by radiograph, CT scan, MRI, nuclear medicine bone scan, or physical examination

No measurable disease allowed if tumor or metastasis has been removed or successfully treated prior to study
No rapidly progressive symptomatic disease affecting major organ systems (e.g., lungs and liver)
Stable or unstable disease for 3 months on hormonal therapy
Stable or unstable disease for at least 1 month after chemotherapy

No active brain metastases

Brain metastases previously treated with definitive radiotherapy and/or surgical resection allowed

Hormone receptor status:

Estrogen and progesterone receptor status known

Phase II:

All Phase I criteria

HER2/neu overexpression (2+ or 3+) by immunohistochemistry

Prior trastuzumab (Herceptin) allowed if disease still overexpresses HER2/neu

PATIENT CHARACTERISTICS:

Age:

18 and over

Sex:

Female

Menopausal status:

Not specified

Performance status:

Karnofsky 70-100% OR
ECOG 0-2

Life expectancy:

At least 3 months

Hematopoietic:

Granulocyte count at least 1,500/mm^3
Platelet count at least 50,000/mm^3
Hemoglobin at least 8 g/dL

Hepatic:

Bilirubin less than 1.5 times normal
SGOT less than 1.5 times normal

Renal:

Creatinine no greater than 1.8 mg/dL
Creatinine clearance at least 60 mL/min
BUN no greater than 1.5 times normal

Cardiovascular:

No myocardial infarction within the past year
No prior myocardial infarction with coronary symptoms requiring medication and/or depressed left ventricular function (LVEF less than 50% by MUGA)
No angina or coronary symptoms requiring medication and/or with depressed left ventricular function (LVEF less than 50% by MUGA)
No congestive heart failure requiring medical management
LVEF at least 50% at rest by MUGA
No uncontrolled hypertension (i.e., systolic blood pressure [BP] ≥ 130 mm Hg or diastolic BP ≥ 80 mm Hg)

Pulmonary:

FEV1, DLCO, and FVC at least 50% predicted

Other:

Not pregnant or nursing
Negative pregnancy test
Fertile patients must use effective contraception
HIV negative
No other serious medical or psychiatric illness that would preclude study participation
No other prior or concurrent malignancy within the past 5 years except curatively treated squamous cell carcinoma in situ of the cervix, basal cell skin cancer, or any other curatively treated disease in complete remission

PRIOR CONCURRENT THERAPY:

Biologic therapy:

See Disease Characteristics
Prior trastuzumab allowed for phase I

Chemotherapy:

See Disease Characteristics
At least 4 weeks since prior chemotherapy

Endocrine therapy:

See Disease Characteristics
Concurrent hormonal therapy for breast cancer must continue during study
No other concurrent hormonal therapy except steroids for adrenal failure, septic shock, or pulmonary toxicity or hormonal therapy for non-disease-related conditions (e.g., insulin for diabetes)

Radiotherapy:

See Disease Characteristics

Surgery:

See Disease Characteristics