Hannover Medical School - Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School - Department of Gastroenterology, Hepatology and Endocrinology, Technische Universität München (TUM), University of Hamburg - University Medical Center Hamburg-Eppendorf, Dresden University of Technology - University Clinic Carl Gustav Carus, Charité - Universitätsmedizin Berlin - Berlin Institute of Health, Oncodoc GmbH, HOPE—Practice for Oncology, HELIOS Hospital, Ludwig Maximilian University of Munich (LMU), Leopoldina Hospital Schweinfurt, Heidelberg University, HOPE—Practice for Oncology, HOPE—Practice for Oncology, HOPE—Practice for Oncology, Department of Hematology, Oncology and Gastroenterology, Maria Hilf Kliniken, University of Greifswald - University Hospital Greifswald, Institut für Klinisch-Onkologische Forschung Krankenhaus Nordwest Frankfurt/Main and Schleswig-Holstein University - University Medical Center