1. Department of Hematology/Oncology and Palliative Care, Klinikum Stuttgart, Stuttgart, Germany;
2. Department of Hematology, Oncology and Stem Cell Transplantation, Faculty of Medicine, University of Freiburg, Freiburg, Germany; and
3. Department of Medical Oncology and
4. Institute for Clinical Epidemiology & Biostatistics, University Hospital Basel, Basel, Switzerland