Assessment of HER2 status in breast cancer: why, when and how?

Human epidermal growth factor receptor 2 (HER2) is overexpressed. usually as a result of HER2 proto-oncogene amplification, in 20-30% of breast cancers. A HER2-positive status is generally associated with mori aggressive disease rind a worse prognosis. Furthermore. a positive HER2 status may predict the likelihood of resistance to some conventional therapies. as well as probably being predictive of sensitivity to anthracycline doss intensification. in addition to this prognostic/predictive the value, HER2 is a target for specific therapy. with anti-HER2 monoclonal antibody therapy available in the USA. This article reviews the different assays used to determine HER2 status. discussing their relative advantages/disadvantages and the need for their standardisation before integration alongside other pathological indicts into the clinical management of breast cancer. (C) 2000 Elsevier Science ltd. All rights reserved.