1. Department of Surgery, Ulm University hospital, Ulm, Germany
2. Department of General and Digestive Surgery—Colorectal Unit, Bellvitge University Hospital, University of Barcelona and IDIBELL, Barcelona, Spain
3. Institute of Medical Biometry, University of Heidelberg, Heidelberg, Germany
4. The Study Center of the German Society of Surgery (SDGC), University of Heidelberg, Heidelberg, Germany
5. Department of Medical Oncology, National Center for Tumor Diseases, Heidelberg University Hospital, Heidelberg, Germany
6. Coordination Centre for Clinical Trials (KKS), University Hospital Heidelberg, Heidelberg, Germany
7. Department of General, Visceral and Transplantation Surgery, University Hospital Augsburg, Augsburg, Germany
8. Department of Medicine I, Agaplesion Markus Hospital, Goethe-University, Frankfurt am Main, Germany
9. Department of Surgery, Community Hospital Kiel, Kiel, Germany
10. Department of Visceral, Thoracic and Vascular Surgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
11. Department of General, Visceral and Transplantation Surgery, Medical Faculty Heidelberg, University Hospital Heidelberg, Heidelberg, Germany
12. Department of Medicine I, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
13. Department of Oncology, Gastroenterology, Hepatology, and Pulmonology, Comprehensive Cancer Center Central Germany (CCCG), University of Leipzig Medical Center, Leipzig, Germany
14. National Center for Tumor Diseases (NCT/UCC), Dresden, Germany