c-erbB2 expression predicts tamoxifen efficacy in breast cancer patients

c-erbB2 is a proto-oncogene that encodes the trans-membrane protein p185. T his protein shares considerable sequence and structure homology with member s of the epidermal growth factor receptor family and it is believed to coop erate with these receptors in the signal transduction process in order to c ontrol cell proliferation. Overexpression of c-erbB2, with or without gene amplification, is frequently found in breast cancer, and a body of evidence suggests it is implicated in the development of resistance to the antiestr ogen tamoxifen. Scientific evidence strongly supports a correlation between c-erbB2 overexpression and lack of efficacy of tamoxifen in both advanced and adjuvant settings. However, given the important therapeutic repercussio n of this topic, further studies are required before c-erbB2 evaluation can be routinely used to select patients who are likely to benefit from tamoxi fen administration.