1. Universitaetsklinikum Essen-Innere Medizin-Essen, Essen, Germany
2. German Cancer Consortium (DKTK), Heidelberg, Germany
3. Sarcoma Center, West German Cancer Center, Essen, Germany
4. Universitätsklinikum Essen, Essen, Germany
5. Department of Medical Oncology, West German Cancer Center, University Hospital Essen, University Duisburg-Essen, Essen, Germany
6. Department of Medical Oncology, West German Cancer Center, University Hospital Essen, Essen, Germany