1. Department of Surgery (A), Heinrich‑Heine‑University and University Hospital D�sseldorf, D‑40225 D�sseldorf, Germany
2. Coordination Centre for Clinical Trials, Heinrich‑Heine‑University and University Hospital D�sseldorf, D‑40225 D�sseldorf, Germany
3. Institute of Pathology, Cytology and Molecular Pathology, D‑51465 Bergisch Gladbach, Germany