Potential of biologically targeted therapies for breast cancer

Despite progress in understanding the molecular and cellular basis of cancer, translation of this information into new therapies has been a complex process. Targeted therapies, which have been used in several disease areas for decades, have only recently been utilised as an approach to treatment. There are many potential targets for therapy. Targets that are under clinical investigation include the family of epidermal growth factor receptors (EGFRs or erbB) as well as vascular endothelial growth factor (VEGF), both of which play an important role in malignant cellular growth. Currently available biological agents with proved efficacy are directed against either EGFRs, VEGF or tyrosine kinases and include trastuzumab, cetuximab, bevacizumab, gefitinib, erlotinib and imatinib. Moreover, the development of agents targeting multiple pathways has resulted in additional effective agents such as lapatinib and enzastaurin. This overview briefly evaluates the promising areas for cancer targeted therapy as well as some of the targeted agents that have already impacted or are just setting out to change treatment paradigms of various malignant disorders.