1. Department of Radiation Oncology, Universitatsklinikum Erlangen, Friedrich-Alexander-Universitat Erlangen-Nürnberg, Erlangen, Germany;
2. Department of General and Visceral Surgery, University Medical Center Goettingen, Goettingen, Germany;
3. Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany;
4. General and Visceral Surgery, University Medical Center Freiburg, Freiburg, Germany;
5. Onkologische Schwerpunktpraxis, Dresden, Germany;
6. Ruhr-University Bochum, St. Josef Hospital, Bochum, Germany;
7. Department of General-, Visceral-, Vascular- and Transplant Surgery, University Hospital Magdeburg, Magdeburg, Germany;
8. Department of General and Visceral Surgery, University Hospital Frankfurt, Frankfurt, Germany;
9. University Hospital RWTH Aachen, Aachen, Germany;
10. Department of Gastroenterology and Hepatology, University of Cologne, Cologne, Germany;
11. Universitätsklinikum der LMU, Medizinische Klinik und Poliklinik III and Comprehensive Cancer Center Munich, München, Germany;
12. Krankenhaus Barmherzige Brüder, Dept. Hematology and Oncology, Regensburg, Germany;
13. Department of Hematology, Oncology and Palliative Care, St. Josef-Hospital, Ruhr-University Bochum, Bochum, Germany;
14. Universitätsklinikum Erlangen, Department of Surgery, Erlangen, Germany;
15. Institut für Medizininformatik, Biometrie und Epidemiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany;
16. Institut für Pathologie der Ruhr-Universität Bochum, Bochum, Germany;
17. Onkologische und Hamatologische Schwerpunktpraxis, Friedrichshafen, Germany;