1. From the Departments of Medical Oncology and Hematology, and Surgery, Kliniken Essen-Mitte; Department of Radiation Oncology, and the Institute for Medical Informatics, Biometry, and Epidemiology, University of Duisburg-Essen Medical School, Essen; Department of Surgery, Klinikum Solingen, Solingen; Departments of Hematology and Oncology, Surgery, and Radiation Oncology, University Clinic, Marburg; and the Department of Gastroenterology, Surgery, and Radiation Oncology, University Clinic, Tübingen,...