Prognostic markers in breast cancer: the reliability of HER2/neu status in core needle biopsy of 325 patients with primary breast cancer

Introduction The assessment of HER2/neu overexpression in tissue provides information about one of the most relevant prognostic and predictive markers in breast cancer: overexpression of HER2/neu is associated with worse prognosis in primary breast cancer. Since core needle biopsy is increasingly used for the diagnosis of breast cancer, the purpose of this study was to assess the reliability of HER2/neu evaluation using this technique in patients with primary breast cancer.