1. Department of Palliative Medicine, University Hospital of Cologne, Cologne, Germany.
2. Clinical Trials Center Cologne, Cologne, Germany.
3. Department of Internal Medicine I, University Hospital of Cologne, Cologne, Germany.
4. Department of Palliative Medicine, University Hospital Erlangen, Erlangen, Germany.
5. Center for Integrated Oncology, University Hospital of Cologne, Cologne, Germany.