1. Spanish National Cancer Research Center (CNIO), Genetic and Molecular Epidemiology Group, Madrid, and CIBERONC, Spain
2. Karolinska Institutet and University Hospital, Gastrocentrum, Stockholm, Sweden
3. Technical University of Munich, Department of Surgery, Munich, Germany
4. University of Heidelberg, Department of Surgery, Heidelberg, Germany
5. Hospital Universitari Vall d’Hebron, Vall d’Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona, and CIBEREHD, Spain
6. Hospital de la Santa Creu i Sant Pau, Department of Gastroenterology, Barcelona, Spain
7. University Hospital 12 de Octubre, Department of Surgery, Madrid, Spain
8. Royal Liverpool University Hospital, Department of Molecular and Clinical Cancer Medicine, Liverpool, UK
9. Hospital del Mar—Parc de Salut Mar, Barcelona, Spain
10. Queen's University Belfast, Centre for Public Health, Belfast, UK
11. Instituto Universitario de Oncología del Principado de Asturias, Department of Medicine, Oviedo, and CIBERESP, Spain
12. University Hospital of Giessen and Marburg, Department of Gastroenterology, Marburg, Germany
13. General University Hospital of Elche, Molecular Genetics Laboratory, Elche, Spain
14. Barts Cancer Institute, Centre for Molecular Oncology, Queen Mary University of London, London, UK
15. University Clinical Hospital of Santiago de Compostela, Department of Gastroenterology, Santiago de Compostela, Spain
16. Salamanca University Hospital, General and Digestive Surgery Department, Salamanca, Spain
17. Martin-Luther-University Halle-Wittenberg, Department of Visceral, Vascular and Endocrine Surgery, Halle (Saale), Germany
18. National Cancer Registry Ireland and HRB Clinical Research Facility, University College Cork, Cork, Ireland
19. ARC-Net Centre for Applied Research on Cancer and Department of Pathology and Diagnostics, University and Hospital Trust of Verona, Verona, Italy
20. Madrid-Norte-Sanchinarro Hospital, Madrid, Spain
21. Newcastle University, Institute of Health and Society, Newcastle upon Tyne, UK
22. Ramón y Cajal University Hospital, Department of Oncology, IRYCIS, Alcala University, Madrid, and CIBERONC, Spain
23. Spanish National Cancer Research Centre (CNIO), Epithelial Carcinogenesis Group, Madrid, Universitat Pompeu Fabra, Departament de Ciències Experimentals i de la Salut, Barcelona, and CIBERONC, Spain