1. Polyposis Registry, St Mark’s Hospital, Harrow, UK
2. Department of Surgery and Cancer, Imperial College London, London, UK
3. Barts Cancer Institute, Queen Mary University of London, London, UK
4. Division of Biomedical Informatics, Department of Medicine, University of California San Diego, La Jolla, California, USA
5. Department of Colorectal Surgery, University College Hospital, London, UK