Vaccine Therapy in Treating Patients With Stage IV Hormone Receptor Positive Breast Cancer

PRIMARY OBJECTIVES: I. To quantify and characterize human epidermal growth factor receptor 2 (HER2)-specific central memory T cell (TCM) and effector memory T cell (TEM) subsets in peripheral blood mononuclear cell (PBMC) of patients vaccinated with a HER2 cytotoxic T lymphocyte (CTL) peptide-based vaccine. II. To evaluate the feasibility of expanding HER2-specific effector T cells (TE) derived from HER2-specific TCM or TEM precursors in patients vaccinated with a HER2 CTL peptide-based vaccine and characterize their function. SECONDARY OBJECTIVES: I. To evaluate the safety of administering a HER2 CTL peptide-based vaccine in patients who are receiving trastuzumab and/or lapatinib (lapatinib ditosylate). OUTLINE: Patients receive HER-2/neu peptide vaccine intradermally (ID) once monthly for 3 months. After completion of study treatment, patients are followed up at 4 weeks.