1. Department of Internal Medicine, section of Gerontology and Geriatrics, Leiden University Medical Center, The Netherlands
2. Department of Internal Medicine, University Medical Center Groningen, The Netherlands
3. Department of Medical Oncology, Leiden University Medical Center, The Netherlands
4. Department of Internal Medicine, Amstelland Hospital, Amstelveen, The Netherlands
5. Department of Radiation Oncology, Leiden University Medical Center, The Netherlands
6. Department of Gastroenterology and Hepatology, Leiden University Medical Center, The Netherlands