1. Department of General Surgery, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
2. Department of Pathology, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
3. Department of Medical Epidemiology, Biometrics and Informatics, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany