1. Department of Gastroenterological Surgery Oslo University Hospital The Radium Hospital Pb 4950 Nydalen 0424 Oslo Norway
2. Department of Gastroenterological Surgery, Oslo University Hospital, The Radium Hospital, Oslo, Norway
3. Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
4. Department of Tumor Biology, Oslo University Hospital, The Radium Hospital, Oslo, Norway