Clinical implications of intratumoral heterogeneity of HER2 gene amplification in locally advanced HER2-positive breast cancer patients

[...]results of recent studies show that the combination of targeted therapy alone, without the addition of chemotherapy, also has activity in a substantial percentage of patients. In general, neoadjuvant chemotherapy causes a recognizable impact on the immunohistochemical expression of different tumor biomarkers, tumor grade, properties of the tumor cells and tumor proliferation rates in breast cancer specimens(6 ,7). Pernas Simon S. Neoadjuvant therapy of early stage human epidermal growth factor receptor 2 positive breast cancer: latest evidence and clinical implications.