[Targeting epidermal growth factor receptor in cancer of the breast]

The erbB receptor family is part of the receptor tyrosine kinase superfamily and consists of four members erbB. The erbB receptor family has been shown to play an important role in both the development of the normal breast and the pathogenesis and progression of breast cancer. Receptor overexpression has also been shown to be a negative prognostic indicator and to correlate with both tumor invasiveness and a lack of responsiveness to standard treatment, both chemotherapy and hormonotherapy. The targeting of EGFR mainly resides in two approaches: tyrosine kinase inhibition and monoclonal antibodies blocking ligand fixation. Many experimental data support the potential role of targeting EGFR in breast cancer. Particularly tyrosine kinase inhibitors demonstrates activity as single agent or in association with hormonotherapy, chemotherapy and trastuzumab. The association of Iressa with hormonotherapy points out that theses agents may prevent or differ hormonoresistance. Moreover studies in situ carcinoma suggest that tyrosine kinase inhibitors may play a role in chemoprevention. So, targeting EGFR may be indicated in a large spectrum of breast tumors from early to advanced stages, hormone negative or positive breast tumors. However the complexity of erbB network requires the targeting of multiple molecular sites within the network and the characterization of tumor profiles in order to optimally select patients for these therapies.