Introduction
HER-2/neu is a 'self' tumor antigen overexpressed in approximately 25-40% of breast/ovarian cancers. Vaccine strategies are an attractive treatment option, although cancer vaccines targeting 'self' tumor antigens must overcome immunological tolerance if they are to be effective. One approach is the use of peptide-based vaccines, which could overcome tolerance to the whole protein by targeting the immune response towards non-immunodominant peptide portions of the antigen. This approach has been shown to be effective in rat models. Studies in rats have also shown that GM-CSF is a potent immune-adjuvant, presumably working via its action on dermal dendritic (antigen-presenting) cells.