1 The Royal Marsden Hospital NHS Foundation Trust, London, UK.
2 2nd Department of Internal Medicine-Gastroenterology, Charles University Faculty of Medicine in Hradec Kralove and University Hospital, Hradec Kralove, Czech Republic.
3 2nd Department of Internal Medicine-Gastroenterology and Geriatrics, Faculty of Medicine and Dentistry, Palacký University Olomouc and University Hospital Olomouc, Czech Republic.