DISEASE CHARACTERISTICS: - Histologically confirmed breast cancer - Stage IV disease - Measurable disease by RECIST criteria - Accessible tumor, defined as a malignant effusion or one of the following disease sites measuring ≥ 2 cm: - Subcutaneous tissue - Superficial lymph nodes - Peripheral lung nodule accessible by video-assisted thoracic surgery - No clinical evidence of CNS disease - Hormone receptor status not specified PATIENT CHARACTERISTICS: - Menopausal status not specified - ECOG performance status 0-2 - Life expectancy > 6 weeks - WBC ≥ 2,000/mm³ - Bilirubin ≤ 2.0 mg/dL - Creatinine ≤ 2.0 mg/dL - Not pregnant or nursing - Negative pregnancy test - Fertile patients must use effective contraception - HIV negative - No clinically significant autoimmune disease - No concurrent serious illness, such as infection requiring IV antibiotics - No significant cardiac disease, including any of the following: - Arrhythmia - Ischemic coronary disease - Congestive heart failure - No history of clinically significant venous thromboembolic disease PRIOR CONCURRENT THERAPY: - No more than 2 prior chemotherapy regimens for metastatic disease - Following enrollment, patients may receive up to 2 courses/months of chemotherapy initiated at the time of vaccine generation - Any number of prior hormonal treatments allowed - More than 4 weeks since prior and no concurrent trastuzumab (Herceptin®) - More than 4 weeks since prior chemotherapy or hormonal therapy - More than 3 months since prior immunotherapy