Serologic Concentrations of HER-2/neu in Breast Cancer Patients with Visceral Metastases Receiving Trastu- zumab Therapy Predict the Clinical Course, Thomas

The HER-2/neu oncoprotein, a member of the epidermal growth factor receptor family, is overexpressed in 20–30% of breast cancer patients as a result of gene amplification (1, 2). Various methods have been used to quantify both HER-2/neu gene amplification and its gene product. Those methods most clinically applicable include fluores-cence in situ hybridization for gene amplification and immunohistochemistry or ELISAs for protein overexpres-sion (3, 4). The amplification/overexpression of HER-2/ neu may have several clinical implications that indicate an aggressive form of breast cancer with a significantly shortened relapse-free interval (1, 2). Nevertheless, the independence of this factor remains uncertain, as does the predictive value of HER-2/neu overexpression for thera-peutic success (5)