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