Personalized Surveillance Protocol for Serrated Polyposis Syndrome
Personalized Surveillance Protocol for Serrated Polyposis Syndrome
Serrated polyposis syndrome (SPS) is a condition characterized by the presence of multiple
 serrated polyps (SPs) spread throughout the colorectum and is associated with an increased
 risk of colorectal cancer (CRC). SPS is defined by the World Health Organization (WHO) as the
 presence of at least 5 SPs proximal to the sigmoid colon, of which 2 ≥10 mm in size (WHO
 criterion 1), the presence of at least 1 SP proximal to the sigmoid and a first degree
 relative with SPS (WHO criterion 2), or more than 20 SPs spread throughout the colon
 (WHO-criterion-3). In practice only WHO 1 and WHO 3 criteria are used.

 The condition seems rather common and more prevalent than other polyposis syndromes such as
 familial adenomatous polyposis (FAP) (1:13.000).

 Several retrospective studies have shown that patients with SPS have an increased risk of
 developing CRC during endoscopic surveillance. Close endoscopic surveillance to prevent
 malignant progression of polyps has therefore been advised by several expert groups. However,
 due to a shortage of prospective data the optimal treatment and surveillance approach is
 largely unknown.

 The current study aims to prospectively evaluate the effectiveness and feasibility of a
 personalized surveillance protocol for patients with SPS to prevent CRC that is being used in
 several Dutch and Spanish hospitals. Furthermore, the polyp burden, colonoscopy complication
 risk and rate of conversion from endoscopic surveillance to colorectal surgery will be
 examined.

 For this purpose, all eligible SPS patients are prospectively enrolled 2013 onwards, and
 surveyed according to the study protocol. Based on the amount and characteristics of the
 polyps encountered during surveillance colonoscopy, the next colonoscopy will be scheduled
 after either 1 year or 2 years.

 Patients will undergo surveillance after 1 year in case of:

 -  Advanced adenoma (≥ 10 mm and/or high-grade dysplasia and/or 25% villous component)

 -  Serrated polyp ≥ 10mm and/or SP containing dysplasia

 -  Cumulative ≥5 sessile serrated polyps (SSPs) (irrespective of size), adenomas
 (irrespective of size) and/or hyperplastic polyps (HPs) ≥5mm

 -  Surgery needed during previous (clearing or surveillance) endoscopy

 Patients will undergo surveillance after 2 years in case none of above is reached
This study has an international multi-centre prospective cohort design. The study will be
 directed by the Academic Medical Centre (AMC), Amsterdam, the Netherlands.

 Population base All patients treated at one of the participating centres will be eligible for
 this study.

 Protocol violations Incomplete endoscopic excision of polyps without proper re-colonoscopy
 Prolonged interval within surveillance colonoscopies (Exceeding protocol with >1 year)

 Sample size calculation No sample size calculation is performed, because of the observational
 design of this study. All eligible patients will be included, unless an exclusion criterion
 is met. The envisioned number of patients to be included is around 500.

 Institutional review board This study is conducted in accordance with the research code of
 our Institutional Review Board (IRB) on human experimentation as well as in agreement with
 the Helsinki Declaration. The IRB decided that the study did not apply to the requirements of
 the Medical Research Involving Human Subjects Act (WMO), as data were collected during
 routine care and no additional patient interventions will be undertaken. Therefore also no
 informed consent is needed for this study. The study protocol will be registered on a
 publicly accessible website register.
Inclusion Criteria:

 -  Patients with SPS WHO 1 criterion (cumulative ≥ 5 histologically diagnosed SPs
 proximal to the sigmoid colon, of which 2 ≥ 10mm in diameter) and/or WHO 3 criterion
 (cumulative ≥ 20 SPs spread throughout the colon, at least 3 of the SPs will have to
 be situated proximal to the sigmoid colon).

 -  Age 18 years or older

 Exclusion Criteria:

 -  - Germline mutation for hereditary colorectal cancer syndrome (e.g. familial
 adenomatous polyposis, Lynch syndrome. Not including heterozygous MUTYH mutation)

 -  Inflammatory bowel disease

 -  Proctocolectomy

 -  History of radiotherapy in abdominal region