1. Department of Medical Oncology, St. George's Hospital NHS Trust, London SW17 0QT, UK
2. Institute of Oncology, St. James's University Hospital, Leeds LS9 7TF, UK
3. Weston Park Cancer Centre, Weston Park Hospital, University of Sheffield, Sheffield S10 2SJ, UK
4. Academic Unit of Clinical Oncology, The University of Sheffield, Sheffield S10 2TN, UK