1. Northern Oesophagogastric Unit, Royal Victoria Infirmary, Newcastle upon Tyne, UK
2. Department of Upper Gastrointestinal Surgery, St. Mary’s Campus, Imperial College London, London, UK
3. Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden
4. Department of Upper Gastrointestinal Surgery, Royal Surrey County Hospital, London, UK
5. Department of Upper Gastrointestinal Surgery, Queen Elizabeth Hospital, Birmingham, UK