Her-2/neu and breast cancer

Breast cancer is the most common malignancy in women in the United States i n the year 2000. The proto-oncogene Her-2/neu (c-erb-B2) has become an incr easingly important prognostic and predictive factor in breast cancer. Overe xpression/amplification of the Her-2/neu has been associated with a worse o utcome in patients with breast cancer. Herceptin, a "humanized" murine mono clonal antibody directed against the extracellular domain of the Her-2/neu protein, is being used to treat breast cancer that overexpresses Her-2/neu. The status of Her-2/neu in the tumor has become a critical factor in the m anagement strategy of a breast cancer patient. The objective of this articl e is to provide a comprehensive review of all aspects of Her-2/neu in breas t cancer, including biology, prognostic and predictive value, targeted Herc eptin therapy, and the laboratory testing of Her-2/neu.