Targeted therapies offer a new approach to breast cancer treatment.
Rather than eliminating both malignant and normal cells
nonspecifically, these so-called “rational” therapies exploit second messenger
proteins, ligands, and receptors that are known to be upregulated
in neoplastic cells, or are implicated in cancer metastasis. This review
will highlight a number of these targets and the mechanisms that have
been targeted in drug design. We will also describe recently completed
and currently ongoing clinical trials investigating targeted therapies
and their potential to augment standard breast cancer therapy.