1. Tumor Center Regensburg, Center of Quality Management and Health Services Research, University of Regensburg, 93053 Regensburg, Germany
2. Bavarian Cancer Registry, Regional Center Regensburg, Bavarian Health and Food Safety Authority, 93053 Regensburg, Germany
3. Arbeitsgemeinschaft Deutscher Tumorzentren e.V. (ADT), 14057 Berlin, Germany
4. Center for Evidence-Based Healthcare (ZEGV), Faculty of Medicine, University Hospital Carl Gustav Carus and Carl Gustav Carus, Dresden University of Technology (TU Dresden), 01307 Dresden, Germany
5. Department of Surgery, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
6. Klinik für Allgemein-, Viszeral-, Thoraxchirurgie und Adipositasmedizin, Caritas Krankenhaus St., 93053 Regensburg, Germany
7. Klinik für Allgemein-, Viszeral-, Thorax- und Kinderchirurgie, 71032 Böblingen, Germany
8. Department of General, Visceral and Thoracic Surgery, Hospital of Neumarkt, 92318 Neumarkt in der Oberpfalz, Germany
9. Klinik für Allgemein- und Viszeralchirurgie, Krankenhaus der Barmherzigen Brüder, 93049 Regensburg, Germany
10. Department of Visceral, Thoracic and Vascular Surgery, University Hospital Carl Gustav Carus Dresden, Faculty of Medicine Carl Gustav Carus, Dresden University of Technology (TU Dresden), 01307 Dresden, Germany
11. WIdO—AOK Research Institute, 10178 Berlin, Germany