Trastuzumab, Cyclophosphamide, and Vaccine Therapy in Treating Patients With High-Risk or Metastatic Breast Cancer

DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the breast, meeting one of the following criteria:
• Metastatic disease
• High-risk disease, defined as early-stage disease with pathologic involvement of locoregional lymph nodes
• Patients who are/will be receiving standard adjuvant trastuzumab [Herceptin®] for high-risk disease will participate in this study during the single-agent trastuzumab portion of their therapy
• No clinical or radiographical evidence of active disease
• Not eligible for therapy of known curative potential for metastatic breast cancer
• HER2/neu-overexpressing disease, defined as HER2/neu positive by IHC 3+ staining or by FISH+ amplification
• Stable CNS disease allowed provided it has been adequately treated and is not under active treatment
• Hormone receptor status not specified

PATIENT CHARACTERISTICS:

• Menopausal status not specified
• ECOG performance status 0-1
• ANC > 1,000/mm^3
• Platelet count > 100,000/mm^3
• Serum creatinine < 2.0 mg/dL
• Serum bilirubin ≤ 2.0 mg/dL (unless elevation is due to known Gilbert's syndrome)
• AST/ALT ≤ 2 times upper limit of normal (ULN)
• Alkaline phosphatase ≤ 5 times ULN
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• Cardiac ejection fraction normal by MUGA OR ≥ 45% by ECHO
• No other malignancies within the past 5 years, except for carcinoma in situ of the cervix, superficial nonmelanoma skin cancer, or superficial bladder cancer
• No prior or currently active autoimmune disease* requiring management with systemic immunosuppression, including any of the following:
• Inflammatory bowel disease
• Systemic vasculitis
• Scleroderma
• Psoriasis
• Multiple sclerosis
• Hemolytic anemia or immune-mediated thrombocytopenia
• Rheumatoid arthritis
• Systemic lupus erythematosus
• Sjögren syndrome
• Sarcoidosis
• Other rheumatologic disease
• No symptomatic intrinsic lung disease or extensive tumor involvement of the lungs resulting in dyspnea at rest
• HIV-negative
• No evidence of active acute or chronic infection
• No uncontrolled medical problems
• No active major medical or psychosocial problems that could be complicated by study participation
• No corn allergy
• No known severe hypersensitivity to trastuzumab (except for mild to moderate infusion reactions that are easily managed and do not recur) NOTE: *Asthma or chronic obstructive pulmonary disease that does not require daily systemic corticosteroids allowed

PRIOR CONCURRENT THERAPY:

• Any number of prior chemotherapy regimens for metastatic breast cancer allowed
• Prior or concurrent trastuzumab in the adjuvant or metastatic setting allowed
• More than 28 days since prior and no concurrent systemic oral steroids
• Topical, ocular, or nasal steroids allowed
• More than 28 days since prior and no concurrent chemotherapy, radiotherapy, or biologic therapy (except trastuzumab)
• More than 28 days since prior and no concurrent participation in another investigational clinical trial involving a new drug
• Concurrent endocrine therapy or bisphosphonates allowed