Her-2/ neu and Breast CancerKaptain, Stamatina M.D.; Tan, Lee K. M.D.; Chen, Beiyun M.D., Ph.D.Author Information From the Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, New York. Address correspondence and reprint requests to Dr. Beiyun Chen, Dept. of Pathology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave., New York, NY 10021 (e-mail: [email protected]). Diagnostic Molecular Pathology: September 2001 - Volume 10 - Issue 3 - pp 139-152 Buy Abstract Breast cancer is the most common malignancy in women in the United States in the year 2000. The proto-oncogene Her-2/ neu (c-erb-B2) has become an increasingly important prognostic and predictive factor in breast cancer. Overexpression/amplification of the Her-2/ neu has been associated with a worse outcome in patients with breast cancer. Herceptin, a “humanized” murine monoclonal 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 management strategy of a breast cancer patient. The objective of this article is to provide a comprehensive review of all aspects of Her-2/ neu in breast cancer, including biology, prognostic and predictive value, targeted Herceptin therapy, and the laboratory testing of Her-2/ neu. © 2001 Lippincott Williams & Wilkins, Inc.