A cell-based cancer vaccine composed of autologous dendritic cells (DCs) transduced with a replication-deficient adenovirus vector encoding HER-2 with potential antineoplastic activity. Upon administration, adenovirus HER2-transduced autologous dendritic cell vaccine may stimulate a cytotoxic T lymphocyte (CTL) response against HER-2-positive tumor cells, which may result in tumor cell death and decreased tumor growth. HER-2, a tyrosine kinase receptor for epidermal growth factor (EGF) (also known as neu and ErbB2), is overexpressed by some breast, ovarian, and gastric cancers.