1. Colorectal Cancer Epidemiology Group, Centre for Epidemiology and Biostatistics, University of Leeds, UK
2. Northern and Yorkshire Cancer Registry and Information Service, St James's Institute of Oncology, St James's Hospital, UK
3. Pathology and Tumour Biology, Leeds Institute for Molecular Medicine, University of Leeds, St James's University Hospital, Leeds, UK
4. National Cancer Services Analysis Team, Clatterbridge Centre for Oncology, Bebington, UK
5. Department of Surgery, University Hospital Aintree, Liverpool, UK