Marie Brevet, Paulo Vidal Campregher, Jesper Bonde, Jon A. Lorentzen, Snjezana Tomić, Anna Long, Elisabeth Bauer, Barbara Dockhorn-Dworniczak, Caroline Chapusot, Ari Ristimäki, Xavier Matias-Guiu, Johanna Wecgowiec, Vanessa Primmer, Nicky D'Haene, Richard Colling, Asaf A Gertler, Elizabeth J. Soilleux, Ana Velasco, George Chong, Serge Nolet, Timo Väisänen, Milo Frattini, Martina Putzova, Ana C Sousa, Fatma Tokat, Chris Wong, Stephen B. Fox, Romena Qazi, Fernando Augusto Soares, Rui Manuel Reis, Matteo Fassan, Astrid Birnbaum, Javier Hernández-Losa, Sabine Merkelbach-Bruse, Michele Biscuola, Afsaneh Soruri, Adam Meeney, Tina Unger, Ryan Yee Wei Teo, Lorand Kis, Wendy W.J. de Leng, Véronique Dalstein, Keeley Thwaites, Michal Kalman, Dirce Maria Carraro, Nicola Trim, Soilleux, Elizabeth [0000-0002-4032-7249], Apollo - University of Cambridge Repository, Pathologies Pulmonaires et Plasticité Cellulaire - UMR-S 1250 (P3CELL), Université de Reims Champagne-Ardenne (URCA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Hospitalier Universitaire de Reims (CHU Reims), Institut Català de la Salut, [Velasco A] Departments of Pathology and Molecular Genetics, Hospital U Arnau de Vilanova and Hospital U de Bellvitge, University of Lleida, IRBLLEIDA, IDIBELL, CIBERONC, 25198 Lleida, Spain. [Tokat F] Department of Pathology, Acıbadem Mehmet Ali Aydınlar University, Istanbul, Turkey. [Bonde J] Molecular Pathology Laboratory, Department of Pathology, afs. 134, Hvidovre Hospital, Hvidovre, Denmark. [Trim N] Molecular Pathology Diagnostic Service, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK. [Bauer E] Städtisches Klinikum Karlsruhe gGmbH, Institut für Pathologie, Karlsruhe, Germany. [Meeney A] Ophthalmic Pathology Laboratory Histopathology, Royal Hallamshire Hospital, Glossop Road, Sheffield, UK. [Hernández-Losa J] Servei de Patologia, Vall d’Hebron Hospital Universitari, Barcelona, Spain. Spanish Biomedical Research Network Centre in Oncology (CIBERONC), Madrid, Spain, Vall d'Hebron Barcelona Hospital Campus, Department of Pathology, HUSLAB, Research Programs Unit, University of Helsinki, Helsinki University Hospital Area, and Acibadem University Dspace
Colorectal cancer; FFPE clinical tissue samples; Microsatellite instability Cancer colorrectal; Muestras de tejido clínico FFPE; Inestabilidad de microsatélites Càncer colorectal; Mostres de teixit clínic FFPE; Inestabilitat del microsatèl·lits Microsatellite instability (MSI) is present in 15–20% of primary colorectal cancers. MSI status is assessed to detect Lynch syndrome, guide adjuvant chemotherapy, determine prognosis, and use as a companion test for checkpoint blockade inhibitors. Traditionally, MSI status is determined by immunohistochemistry or molecular methods. The Idylla™ MSI Assay is a fully automated molecular method (including automated result interpretation), using seven novel MSI biomarkers (ACVR2A, BTBD7, DIDO1, MRE11, RYR3, SEC31A, SULF2) and not requiring matched normal tissue. In this real-world global study, 44 clinical centers performed Idylla™ testing on a total of 1301 archived colorectal cancer formalin-fixed, paraffin-embedded (FFPE) tissue sections and compared Idylla™ results against available results from routine diagnostic testing in those sites. MSI mutations detected with the Idylla™ MSI Assay were equally distributed over the seven biomarkers, and 84.48% of the MSI-high samples had ≥ 5 mutated biomarkers, while 98.25% of the microsatellite-stable samples had zero mutated biomarkers. The concordance level between the Idylla™ MSI Assay and immunohistochemistry was 96.39% (988/1025); 17/37 discordant samples were found to be concordant when a third method was used. Compared with routine molecular methods, the concordance level was 98.01% (789/805); third-method analysis found concordance for 8/16 discordant samples. The failure rate of the Idylla™ MSI Assay (0.23%; 3/1301) was lower than that of referenced immunohistochemistry (4.37%; 47/1075) or molecular assays (0.86%; 7/812). In conclusion, lower failure rates and high concordance levels were found between the Idylla™ MSI Assay and routine tests.