1. Department of Medical Oncology, Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, The Netherlands
2. Department of Gastroenterological Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
3. Department of Medical Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands
4. Department of Pathology, Netherlands Cancer Institute, Amsterdam, The Netherlands
5. Department of Medical Oncology, University Medical Centre Groningen, Groningen, The Netherlands
6. Department of Medical Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands