1. Aristotle University of Thessaloniki, Greece
2. 1Surgical Department, Friedrich-Alexander University of Erlangen-Nuremberg, Germany
3. Institute of Pathology, Friedrich-Alexander University of Erlangen-Nuremberg, Germany
4. Department of Radiation Oncology, Universitätsklinikum Erlangen, Germany
5. Department of Internal Medicine 1 - Gastroenterology, Pulmonology and Endocrinology, Friedrich-Alexander University Erlangen-Nuremberg, Germany
6. Brandenburg Medical School, Department of Surgery, University Hospital, Brandenburg/Havel, Germany