1. Multi-center real-world comparison of the fully automated Idylla™ microsatellite instability assay with routine molecular methods and immunohistochemistry on formalin-fixed paraffin-embedded tissue of colorectal cancer
- Author
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Velasco, A, Tokat, F, Bonde, J, Trim, N, Bauer, E, Meeney, A, de Leng, W, Chong, G, Dalstein, V, Kis, LL, Lorentzen, JA, Tomic, S, Thwaites, K, Putzova, M, Birnbaum, A, Qazi, R, Primmer, V, Dockhorn-Dworniczak, B, Hernandez-Losa, J, Soares, FA, Gertler, AA, Kalman, M, Wong, C, Carraro, DM, Sousa, AC, Reis, RM, Fox, SB, Fassan, M, Brevet, M, Merkelbach-Bruse, S, Colling, R, Soilleux, E, Teo, RYW, D'Haene, N, Nolet, S, Ristimaki, A, Vaisanen, T, Chapusot, C, Soruri, A, Unger, T, Wecgowiec, J, Biscuola, M, Frattini, M, Long, A, Campregher, P, Matias-Guiu, X, Velasco, A, Tokat, F, Bonde, J, Trim, N, Bauer, E, Meeney, A, de Leng, W, Chong, G, Dalstein, V, Kis, LL, Lorentzen, JA, Tomic, S, Thwaites, K, Putzova, M, Birnbaum, A, Qazi, R, Primmer, V, Dockhorn-Dworniczak, B, Hernandez-Losa, J, Soares, FA, Gertler, AA, Kalman, M, Wong, C, Carraro, DM, Sousa, AC, Reis, RM, Fox, SB, Fassan, M, Brevet, M, Merkelbach-Bruse, S, Colling, R, Soilleux, E, Teo, RYW, D'Haene, N, Nolet, S, Ristimaki, A, Vaisanen, T, Chapusot, C, Soruri, A, Unger, T, Wecgowiec, J, Biscuola, M, Frattini, M, Long, A, Campregher, P, and Matias-Guiu, X
- Abstract
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.
- Published
- 2021