1. Department of Social Medicine, University of Bristol, UK
2. Division of Surgery, Head and Neck, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
3. Division of Applied Health Sciences, University of Aberdeen, Aberdeen, UK
4. Department of Cancer Research and Molecular Medicine, Norwegian University of Technology and Science, Trondheim, Norway
5. Department of Medical Oncology, Centre Alexis Vautrin, Nancy, France
6. Department of Oncology and Haematology, University Hospital Charité, Berlin, Germany
7. Department of Hepatobiliary Surgery, North Hampshire Hospital, Basingstoke, UK