University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht, The Netherlands. Netherlands Comprehensive Cancer Organisation (IKNL), Utrecht, The Netherlands. University Medical Center Utrecht, Cancer Center, Utrecht, The Netherlands. Department of Medical Oncology, St. Antonius Hospital, Nieuwegein, The Netherlands. Department of Internal Medicine-Medical Oncology, Orbis Medical Center, Sittard-Geleen, The Netherlands. Department of Internal Medicine, Medical Center Amersfoort, Amersfoort, The Netherlands. Department of Surgery, Hospital Rivierenland, Tiel, The Netherlands. Department of Internal Medicine, Hofpoort Hospital, Woerden, The Netherlands. Department of Internal Medicine, Diakonessenhuis, Utrecht, The Netherlands. School of Public Health, Imperial College London, London, UK. Centre for Nutrition, Prevention and Healthcare, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.