SO34: A reassessment colonoscopy increases the diagnostic yield for serrated polyposis syndrome in a faecal immunochemical test (FIT)-based colorectal cancer screening population

Liseth Rivero-Sanchez1,2, Maria Lopez-Ceron1, Sabela Carballal1, Leticia Moreira1, Xavier Bessa3, Anna Serradesanferm4, Angels Pozo4, Josep Maria Augé5, Teresa Ocaña1, María Liz Leoz1, Míriam Cuatrecasas6,  Jaume Grau4, Josep Llach1, Antoni Castells1, Francesc Balaguer1, Maria Pellisé1.

1 – Department of Gastroenterology, Hospital Clínic de Barcelona. Centro de Investigación Biomédica en Red en Enfermedades Hepáticas y Digestivas (CIBEREHD). Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS). Universitat de Barcelona. Barcelona, Spain. 2 – Fundació Clínic per a la Recerca Biomédica (FCRB). Barcelona, Spain. 3 – Department of Gastroenterology, Hospital del Mar. Barcelona, Spain. 4 – Preventive Medicine and Hospital Epidemiology Department, Hospital Clínic de Barcelona. Barcelona, Spain. 5 – Biochemistry Department, Hospital Clínic de Barcelona. Barcelona, Spain. 6 – Pathology Department, Hospital Clínic de Barcelona. Barcelona, Spain


Serrated polyposis syndrome(SPS) is under diagnosed despite being a high risk condition for colorectal cancer. Surveillance strategies for patients with serrated lesions (SLs) remain controversial. We aim to evaluate the yield of a Reassessment Colonoscopy(RC) to detect SPS in patients with proximal-SLs.


Retrospective study of all individuals with ≥1SL≥5mm proximal to sigmoid-colon at index-colonoscopy from a FIT-based colorectal cancer-screening program (2010-2013). We analysed individuals empirically scheduled to a RC within one year directed to detect SPS.RC was performed with standard white-light(WL) or chromoendoscopy+/-high-definition(CE-HD) following availability. SPS diagnosis was based on cumulative number of polyps in both index-colonoscopy and RC. Factors associated with SPS diagnosis were analysed.


From 196 patients, 71 underwent RC in 11.9±1.7 months. RC helped to diagnose 20/71(28%) new SPS patients.Independent features associated with SPS diagnosis were the presence of ≥5 proximal-SLs(OR=4.01[1.20-13.45];p=0.024) or ≥2 sessile serrated polyps ≥10mm(OR=6.35[1.40-28.81];p=0.016) at index-colonoscopy and the use of CE-HD at RC(OR=4.99[1.11-22.36];p=0.036).


A RC using CE-HD substantially improves SPS detection in individuals with proximal SLs from a FIT-based screening-program. Having ≥5 proximal-SLs or ≥2 sessile serrated polyps ≥10mm at index-colonoscopy could be thresholds to indicate a RC. Further prospective studies are required to validate these results and adjust surveillance recommendations in patients with SLs.