The impact of HER2 phenotype of circulating tumor cells in metastatic breast cancer: a retrospective study in 107 patients

1 Department of Obstetrics and Gynecology, University of Heidelberg, Im Neuenheimer Feld 440, Heidelberg, 69120, Germany

2 Department of Obstetrics and Gynecology, University of Tübingen, Calwerstraße 7, Tübingen, 72076, Germany

3 Department of Tumor Biology, University Medical Center Hamburg-Eppendorf, Martinistraße 52, Hamburg, 20246, Germany

4 National Center for Tumor Diseases, Im Neuenheimer Feld 460, Heidelberg, 69120, Germany

5 Heidelberg Institute for Stem Cell Technology and Experimental Medicine (HI-STEM gGmbH), Im Neuenheimer Feld 280, Heidelberg, 69120, Germany

6 Division of Stem Cells and Cancer, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, 69120, Germany