1. Department of Surgery, Cancer Center Amsterdam, Amsterdam, The Netherlands
2. Department of Surgery, Cancer Center Amsterdam, Amsterdam UMC, VU University, Amsterdam, The Netherlands
3. Department of Surgery, OLVG, Amsterdam, The Netherlands
4. Department of Surgery, Erasmus MC, Rotterdam, The Netherlands
5. Department of Surgery, University Medical Center Groningen, Groningen, The Netherlands
6. Department of Surgery, Catharina Hospital, Eindhoven, The Netherlands
7. Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
8. Department of Surgery, St Antonius Hospital, Nieuwegein, and University Medical Centre Utrecht, Utrecht, the Netherlands
9. Department of Surgery, University Medical Centre Groningen, Groningen, the Netherlands
10. Department of Surgery, St Antonius Hospital, Nieuwegein, the Netherlands
11. Department of Surgery, Radboud University Medical Centre, Nijmegen, the Netherlands
12. Department of Surgery, Maastricht University Medical Centre, Maastricht, the Netherlands
13. Universitätsklinikum Aachen, Aachen, Germany
14. Department of Surgery, Medisch Spectrum Twente, Enschede, the Netherlands
15. Department of Surgery, Erasmus University Medical Centre, Rotterdam, the Netherlands
16. Department of Surgery, OLVG, Amsterdam
17. Departments of Surgery, Catharina Hospital, Eindhoven, Netherlands Comprehensive Cancer Organisation, Utrecht, the Netherlands
18. Department of Surgery, Cancer Centre Amsterdam, Amsterdam UMC, VU University, Amsterdam, the Netherlands
19. Department of Surgery, Isala Clinics, Zwolle, the Netherlands
20. Department of Surgery, Southampton University Medical Centre NHS Foundation Trust, Southampton, UK