1. Department of Surgery, University of Toronto, Toronto, Ontario, Canada
2. Department of Community Health and Epidemiology, Queen’s University, Kingston, Ontario, Canada3Sunnybrook Research Institute, Toronto, Ontario, Canada
3. Department of Surgery, Dalhousie University, Halifax, Canada
4. Institute for Clinical Effectiveness Studies, Toronto, Ontario, Canada
5. Sunnybrook Research Institute, Toronto, Ontario, Canada
6. Department of Surgery, Maimonides Medical Center, Brooklyn, New York
7. Department of Surgery, Brown University, Providence, Rhode Island
8. Department of Gastroenterology Surgery, São Paulo Federal University, São Paulo, Brazil
9. Departments of Medicine and Pharmacology, Ohio State University, Columbus
10. Department of Medicine, Royal Marsden Hospital, Sutton, Surrey, United Kingdom
11. Department of Surgery, University of Calgary, Calgary, Alberta, Canada
12. Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York
13. Department of Radiation Oncology, MD Anderson Cancer Center, Houston, Texas
14. Institute for Clinical Effectiveness Studies, Toronto, Ontario, Canada14Department of Medicine, University of Toronto, Toronto, Ontario, Canada
15. Department of Surgical Oncology, MD Anderson Cancer Center, Houston, Texas
16. Department of Medicine, University of Toronto, Toronto, Ontario, Canada
17. Department of Surgery, Yonsei University College of Medicine, Seoul, South Korea
18. Department of Surgery, University of Chicago, Chicago, Illinois
19. Department of Surgery, Cancer Institute Hospital, Tokyo, Japan
20. Department of Surgery, Leiden University Medical Centre, Leiden, the Netherlands
21. Department of Surgery, University of Michigan Health System, Ann Arbor
22. Department of Surgery, University of Toronto, Toronto, Ontario, Canada3Sunnybrook Research Institute, Toronto, Ontario, Canada5Institute for Clinical Effectiveness Studies, Toronto, Ontario, Canada