Trastuzumab and Interleukin-2 in Treating Patients With Metastatic Breast Cancer

Inclusion Criteria: * Histologically or cytologically confirmed breast cancer * Primary and/or metastatic disease * HER2 overexpression 3+ by immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH) * Tumors with HER2 2+ overexpression by IHC allowed if confirmed by FISH * Progressive disease during or within 12 months of receiving prior regimen containing trastuzumab (Herceptin) * Unidimensionally measurable disease * At least 20 mm by conventional techniques OR at least 10 mm by spiral CT scan * The following are not considered measurable: * Bone metastases * Pleural or peritoneal effusion * Ascites * Leptomeningeal disease * Lymphangitic disease * Inflammatory breast cancer * Cystic lesions * CNS lesions * CNS metastases allowed if all of the following conditions are met: * Asymptomatic * At least 3 months since prior surgery and/or cranial irradiation * At least 3 weeks since prior steroids * Hormone receptor status: * Not specified * Male or female * Performance status - ECOG 0-2 * Granulocyte count at least 1,000/mm\^3 * Platelet count at least 100,000/mm\^3 * Bilirubin no greater than 1.5 times upper limit of normal (ULN) * SGOT and SGPT no greater than 2 times ULN (5 times ULN for liver metastases) * Alkaline phosphatase no greater than 2 times ULN (5 times ULN for liver metastases) * Creatinine no greater than 1.5 times ULN * LVEF at least lower limit of normal by MUGA or echocardiogram * No congestive heart failure or active ischemic heart disease * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No psychiatric illness, medical condition, or uncontrolled infection that would preclude study * No underlying immunodeficiency (e.g., HIV or autoimmune disease) * No other prior malignancy within the past 5 years except nonmelanoma skin cancer or carcinoma in situ of the cervix * See Disease Characteristics * Prior cumulative doxorubicin dose no greater than 360 mg/m\^2 * At least 3 weeks since prior chemotherapy * No more than 2 prior chemotherapy regimens for metastatic disease * No concurrent chemotherapy * See Disease Characteristics * At least 3 weeks since prior endocrine therapy * No concurrent corticosteroids or dexamethasone * Concurrent hormones allowed for conditions unrelated to disease (e.g., insulin for diabetes) * See Disease Characteristics * At least 3 weeks since prior radiotherapy * No prior radiotherapy to study lesion, unless evidence of disease progression * No concurrent palliative radiotherapy * See Disease Characteristics * At least 4 weeks since prior major surgery * No concurrent immunosuppressive drugs