1. Department of Surgery and Cancer, Imperial College London, London SW7 2BX, UK
2. Department of General Surgery, Chelsea and Westminster Hospital, London SW10 9NH, UK
3. Department of Advanced Medical and Surgical Sciences, University of Campania “Luigi Vanvitelli”, 80138 Naples, Italy
4. Department of Surgery, The Royal Marsden Hospital, London SW3 6JJ, UK
5. 2nd Surgical Department, Evangelismos General Hospital, 10676 Athens, Greece