Breast cancer research and treatment
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Breast Cancer Res. Treat. · May 2008
Randomized Controlled Trial Multicenter StudyHER2 status in hormone receptor positive premenopausal primary breast cancer adds prognostic, but not tamoxifen treatment predictive, information.
Overexpression of human epidermal growth factor receptor 2 (HER2) or amplification of its gene is a prognostic factor in primary breast cancer and a predictor for tamoxifen treatment efficacy in oestrogen receptor (ER) positive disease. In the present study we explored a defined cohort of breast cancer patients included in a randomised trial in order to assess prognostic and tamoxifen treatment information yielded by HER2 status. ⋯ HER2+ and ER+ breast cancer constituted a subgroup of tumours with poor prognosis in premenopausal breast cancer, whereas no treatment interaction was found between HER2 status and tamoxifen in ER+ tumours. The poor prognosis in HER2+ and ER+ patients may interfere with the interpretation of HER2 data in non-randomised trials of adjuvant tamoxifen.