Institution: | aDepartment of Medicine, Sorlandet Hospital Kristiansand, Kristiansand, Norway;bDepartment of Medicine, Sorlandet Hospital Arendal, Arendal, Norway;cDepartment of Medicine, Telemark Hospital, Skien, Norway;dThe Cancer Registry of Norway, Oslo, Norway;eDepartment of Gastroenterology, Oslo University Hospital Rikshospitalet, Oslo, Norway |