1. Department of Research & Development Netherlands Comprehensive Cancer Organization (IKNL) Utrecht The Netherlands
2. Netherlands Association for Palliative Care (PZNL) Utrecht The Netherlands
3. Department of Medical Oncology Viecuri Medical Centre Venlo The Netherlands
4. Department of Medical Oncology Zuyderland Hospital Heerlen The Netherlands
5. Department of Surgery Elisabeth Tweesteden Hospital Tilburg The Netherlands
6. Department of Radiation Oncology University Medical Center Utrecht, Utrecht University Utrecht The Netherlands
7. Department of Medical Oncology Gelre Hospital Apeldoorn The Netherlands
8. Department of Surgery Hospital group Twente Almelo The Netherlands
9. Department of Primary and Community Care Radboud university medical center Nijmegen The Netherlands
10. SPKS Leven met maag‐ of slokdarmkanker Utrecht The Netherlands
11. Department of Radiation Oncology Cancer Center Amsterdam, Amsterdam UMC, University of Amsterdam Amsterdam The Netherlands
12. Department of Medical Oncology Cancer Center Amsterdam, Amsterdam UMC, University of Amsterdam Amsterdam The Netherlands
13. Department of Surgery Radboud University Medical Center Nijmegen The Netherlands
14. Department of Gastroenterology and Hepatology Radboud University Medical Center Nijmegen The Netherlands
15. Department of Epidemiology and Biostatistics Amsterdam UMC Amsterdam The Netherlands
16. Department of Surgery Catharina Hospital Eindhoven The Netherlands