HER-2/neu evaluation in breast cancer are we there yet?

The HER-2/neu oncogene is located on chromosome 17q and encodes a transmembrane glycoprotein with intracellular tyrosine kinase activity. Several studies have shown an association of HER-2 gene amplification or protein overexpression with prognosis and predictor of therapeutic response. Most important, the presence of amplification or overexpression is the basis of eligibility for trastuzumab therapy.