title: Increased colorectal cancer risk during follow-up in patients with hyperplastic polyposis syndrome: a multicentre cohort study.
abstract: OBJECTIVE
  Patients with hyperplastic polyposis syndrome (HPS) receive endoscopic surveillance to prevent malignant progression of polyps. However, the optimal treatment and surveillance protocol for these patients is unknown. The aim of this study was to describe the clinical and pathological features of a large HPS cohort during multiple years of endoscopic surveillance.
  
  
  METHODS
  Databases were searched for patients with HPS, who were analysed retrospectively. Endoscopy reports and histopathology reports were collected to evaluate frequency of endoscopic surveillance and to obtain information regarding polyp and the presence of colorectal cancer (CRC).
  
  
  RESULTS
  In 77 patients with HPS, 1984 polyps were identified during a mean follow-up period of 5.6 years (range: 0.5-26.6). In 27 (35%) patients CRC was detected of which 22 (28.5%) at initial endoscopy. CRC was detected during surveillance in five patients (cumulative incidence: 6.5%) after a median follow-up time of 1.3 years and a median interval of 11 months. Of these interval CRCs, 4/5 were detected in diminutive serrated polyps (range: 4-16 mm). The cumulative risk of CRC under surveillance was 7% at 5 years. At multivariate logistic regression, an increasing number of hyperplastic polyps (OR 1.05, p=0.013) and serrated adenomas (OR 1.09, p=0.048) was significantly associated with CRC presence.
  
  
  CONCLUSIONS
  HPS patients undergoing endoscopic surveillance have an increased CRC risk. The number of serrated polyps is positively correlated with the presence of CRC in HPS, thus supporting a 'serrated pathway' to CRC. To prevent malignant progression, adequate detection and removal of all polyps seems advisable. If this is not feasible, surgical resection should be considered.
authors.affiliation: Departments of Gastroenterology and Hepatology, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Karam S
authors.initials: KS
authors.lastname: Boparai
authors.forename: Elisabeth M H
authors.initials: EM
authors.lastname: Mathus-Vliegen
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Koornstra
authors.forename: Fokko M
authors.initials: FM
authors.lastname: Nagengast
authors.forename: Monique
authors.initials: M
authors.lastname: van Leerdam
authors.forename: Carel J M
authors.initials: CJ
authors.lastname: van Noesel
authors.forename: Martin
authors.initials: M
authors.lastname: Houben
authors.forename: Annemieke
authors.initials: A
authors.lastname: Cats
authors.forename: Liselotte P
authors.initials: LP
authors.lastname: van Hest
authors.forename: Paul
authors.initials: P
authors.lastname: Fockens
authors.forename: Evelien
authors.initials: E
authors.lastname: Dekker
mesh_terms: D000328:Adult; D000368:Aged; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D018450:Disease Progression; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D044483:Intestinal Polyposis / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011379:Prognosis; D013577:Syndrome