title: Clinical risk factors of colorectal cancer in patients with serrated polyposis syndrome: a multicentre cohort analysis.
abstract: Serrated polyposis syndrome (SPS) is accompanied by an increased risk of colorectal cancer (CRC). Patients fulfilling the clinical criteria, as defined by the WHO, have a wide variation in CRC risk. We aimed to assess risk factors for CRC in a large cohort of patients with SPS and to evaluate the risk of CRC during surveillance.
  
  
  
  In this retrospective cohort analysis, all patients with SPS from seven centres in the Netherlands and two in the UK were enrolled. WHO criteria were used to diagnose SPS. Patients who only fulfilled WHO criterion-2, with IBD and/or a known hereditary CRC syndrome were excluded.
  
  
  
  In total, 434 patients with SPS were included for analysis; 127 (29.3%) were diagnosed with CRC. In a per-patient analysis ≥1 serrated polyp (SP) with dysplasia (OR 2.07; 95% CI 1.28 to 3.33), ≥1 advanced adenoma (OR 2.30; 95% CI 1.47 to 3.67) and the fulfilment of both WHO criteria 1 and 3 (OR 1.60; 95% CI 1.04 to 2.51) were associated with CRC, while a history of smoking was inversely associated with CRC (OR 0.36; 95% CI 0.23 to 0.56). Overall, 260 patients underwent surveillance after clearing of all relevant lesions, during which two patients were diagnosed with CRC, corresponding to 1.9 events/1000 person-years surveillance (95% CI 0.3 to 6.4).
  
  
  
  The presence of SPs containing dysplasia, advanced adenomas and/or combined WHO criteria 1 and 3 phenotype is associated with CRC in patients with SPS. Patients with a history of smoking show a lower risk of CRC, possibly due to a different pathogenesis of disease. The risk of developing CRC during surveillance is lower than previously reported in literature, which may reflect a more mature multicentre cohort with less selection bias.
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: J E G
authors.initials: JE
authors.lastname: IJspeert
authors.affiliation: The Polyposis Registry, St Mark's Hospital, London, UK.
authors.forename: S A Q
authors.initials: SA
authors.lastname: Rana
authors.affiliation: Translational Gastroenterology Unit, Experimental Medicine Division, Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK.
authors.forename: N S S
authors.initials: NS
authors.lastname: Atkinson
authors.affiliation: Department of Gastroenterology and Hepatology, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: Y J
authors.initials: YJ
authors.lastname: van Herwaarden
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: B A J
authors.initials: BA
authors.lastname: Bastiaansen
authors.affiliation: Department of Gastroenterology and Hepatology, Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: M E
authors.initials: ME
authors.lastname: van Leerdam
authors.affiliation: Division of Gastroenterology and Hepatology, GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Sanduleanu
authors.affiliation: Department of Gastroenterology and Hepatology, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: T M
authors.initials: TM
authors.lastname: Bisseling
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus University Medical Centre, Rotterdam, The Netherlands.
authors.forename: M C W
authors.initials: MC
authors.lastname: Spaander
authors.affiliation: The Polyposis Registry, St Mark's Hospital, London, UK.
authors.forename: S K
authors.initials: SK
authors.lastname: Clark
authors.affiliation: Department of Pathology, Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: G A
authors.initials: GA
authors.lastname: Meijer
authors.affiliation: Department of Gastroenterology and Hepatology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: van Lelyveld
authors.affiliation: Department of Gastroenterology and Hepatology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: J J
authors.initials: JJ
authors.lastname: Koornstra
authors.affiliation: Department of Pathology, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: I D
authors.initials: ID
authors.lastname: Nagtegaal
authors.affiliation: Translational Gastroenterology Unit, Experimental Medicine Division, Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: East
authors.affiliation: The Polyposis Registry, St Mark's Hospital, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Latchford
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Dekker
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*; D011125:Adenomatous Polyposis Coli / Q000453:epidemiology / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011159:Population Surveillance; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology; D014944:World Health Organization; D055815:Young Adult
keywords: COLONIC POLYPS; COLONOSCOPY; COLORECTAL CANCER; POLYPOSIS; SURVEILLANCE