Vaccine Therapy in Treating Patients With Stage IV HLA-A2 and HER2 Positive Breast or Ovarian Cancer Receiving Trastuzumab

PRIMARY OBJECTIVES: I. To evaluate the safety of administering a HER2 cytotoxic T-cell (CTL) peptide-based vaccine (HER-2/neu peptide vaccine) to stage IV breast and ovarian cancer patients receiving maintenance trastuzumab. II. To quantify and characterize antigen specific T cell subsets specific to HER2 in peripheral blood mononuclear cell (PBMC) of patients after vaccination with a HER2 CTL peptide-based vaccine while receiving maintenance trastuzumab. SECONDARY OBJECTIVES: I. To evaluate overall survival (OS) in patients who complete a vaccination series with a HER2 CTL peptide-based vaccine while receiving maintenance trastuzumab. OUTLINE: Patients receive HER-2/neu peptide vaccine intradermally (ID) once per month for 6 months in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 1, 3, 6, and 12 months, and then yearly for up to 5 years.