1. Department of Medical Oncology; Radboud University Medical Center; Nijmegen The Netherlands
2. Department of Medical Oncology; VU University Medical Center; Amsterdam The Netherlands
3. Department of Otorhinolaryngology/Head and Neck Surgery; Erasmus University Medical Center; Rotterdam The Netherlands
4. Department of Head and Neck Surgical Oncology; University Medical Center Utrecht; Utrecht The Netherlands
5. Department of Medical Oncology; Medical Center Leeuwarden; Leeuwarden The Netherlands
6. Department of Medical Oncology; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
7. Department of Medical Oncology; Leiden University Medical Center; Leiden The Netherlands
8. Department of Medical Oncology; Maastricht University Medical Center; Maastricht The Netherlands
9. Department of Medical Oncology; Netherlands Cancer Institute; Amsterdam The Netherlands
10. Department for Health Evidence; Radboud University Medical Center; Nijmegen The Netherlands
11. Department of Pathology; Radboud University Medical Center; Nijmegen The Netherlands
12. The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust; London UK