1. Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands and Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, USA
2. Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands
3. Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, USA
4. Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, USA
5. Department of Radiotherapy, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands
6. Department of Gastroenterology and Hepatology, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, P.O. Box 90203, 1006 BE Amsterdam, The Netherlands