Vaccine Therapy in Treating Patients With HER2/Neu Positive or Negative Stage IV Breast Cancer or Other HER2/Neu Positive Cancers

RATIONALE: Vaccines made from gene-modified tumor cells may make the body build an immune response to kill tumor cells. Drugs used in chemotherapy, such as cyclophosphamide, work in different ways to stop tumor cells from dividing so they stop growing or die. Interferon alfa may interfere with the growth of tumor cells. Combining vaccine therapy with cyclophosphamide and interferon alfa may kill more tumor cells. PURPOSE: Phase I trial to study the effectiveness of combining vaccine therapy with interferon alfa and cyclophosphamide in treating patients who have stage IV breast cancer.