Related Experiment Video For Lynch syndrome
Updated: Jul 4, 2025
Evaluation of Colorectal Cancer Risk and Prevalence by Stool DNA Integrity Detection
Published on: June 8, 2020
Deficient mismatch repair screening of advanced adenomas in the population screening program for colorectal cancer is
Elisa Vink-Börger1, Parag D Dabir2, Joyce Krekels1
1Department of Pathology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
Aim:
Currently, screening of colorectal cancers (CRC) by assessing mismatch repair deficiency (dMMR) or microsatellite instability (MSI) is used to identify Lynch syndrome (LS) patients. Advanced adenomas are considered immediate precursor lesions of CRC. In this study we investigate the relevance of screening of advanced adenomas for LS in population screening.
Methods And Results:
Advanced adenomas (n = 1572) were selected from the Dutch colorectal cancer population screening programme, based on one or more of the criteria: tubulovillous (n = 848, 54%) or villous adenoma (n = 118, 7.5%), diameter ≥ 1 cm (n = 1286, 82%) and/or high-grade dysplasia (n = 176, 11%). In 86 cases (5%), all three criteria were fulfilled at the same time. MMR-IHC and/or MSI analyses were performed on all cases. Only five advanced adenomas (0.3%) showed dMMR and MSI, including two cases with hypermethylation. In at least two patients a germline event was suspected based on allelic frequencies. No pathogenic explanation was found in the last case.
Conclusion:
Timely testing of precursor lesions would be preferable to detect new LS patients before CRC development. However, standard assessment of dMMR of advanced adenomas from the population screening is not effective.
