1   Department of Gastroenterology and Hepatology, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands (Ringgold ID: RIN1234)

2   Cancer Center Amsterdam, Amsterdam, the Netherlands

3   Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, the Netherlands (Ringgold ID: RIN1234)

,

4   Gastrounit, Copenhagen University Hospital - Amager and Hvidovre, Danish Polyposis Registry, Hvidovre, Denmark (Ringgold ID: RIN53137)

5   Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark (Ringgold ID: RIN4321)

,

Barbara A.J. Bastiaansen

1   Department of Gastroenterology and Hepatology, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands (Ringgold ID: RIN1234)

2   Cancer Center Amsterdam, Amsterdam, the Netherlands

3   Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, the Netherlands (Ringgold ID: RIN1234)

,

Monique E. van Leerdam

6   Department of Gastrointestinal Oncology, Netherlands Cancer Institute, Amsterdam, the Netherlands

7   Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, the Netherlands (Ringgold ID: RIN4501)

,

Francesc Balaguer

8   Department of Gastroenterology, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), University of Barcelona, Hospital Clínic de Barcelona, Barcelona, Spain

,

Michal Kaminski

9   Department of Oncological Gastroenterology and Department of Cancer Prevention, Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland

,

Roel Hompes

10   Department of Surgery, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands

2   Cancer Center Amsterdam, Amsterdam, the Netherlands

,

Patrick M.M. Bossuyt

11   Department of Epidemiology and Data Science, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands (Ringgold ID: RIN26066)

,

Luigi Ricciardiello

12   Policlinico di Sant'Orsola, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy

13   Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy (Ringgold ID: RIN9296)

,

14   Polyposis Registry, St Mark's Hospital, Harrow, United Kingdom

15   Department of Surgery and Cancer, Imperial College London, London, United Kingdom (Ringgold ID: RIN4615)

,

Rodrigo Jover

16   Instituto de Investigación Biomédica ISABIAL, Universidad Miguel Hernández, Servicio de Medicina Digestiva, Hospital General Universitario de Alicante, Alicante, Spain (Ringgold ID: RIN16802)

,

8   Department of Gastroenterology, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), University of Barcelona, Hospital Clínic de Barcelona, Barcelona, Spain

,

8   Department of Gastroenterology, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), University of Barcelona, Hospital Clínic de Barcelona, Barcelona, Spain

,

1   Department of Gastroenterology and Hepatology, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands (Ringgold ID: RIN1234)

2   Cancer Center Amsterdam, Amsterdam, the Netherlands

3   Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, the Netherlands (Ringgold ID: RIN1234)

,

TRIAL REGISTRATION: Registration number (trial ID): NCT04677998, Trial registry: ClinicalTrials.gov (http://www.clinicaltrials.gov/), Type of Study: Prospective