RT Journal Article
SR Electronic
T1 Frequency of microsatellite instability (MSI) in upper tract urothelial carcinoma: comparison of the Bethesda panel and the Idylla MSI assay in a consecutively collected, multi-institutional cohort
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 126
OP 132
DO 10.1136/jclinpath-2021-207855
VO 76
IS 2
A1 Kullmann, Friederike
A1 Strissel, Pamela L
A1 Strick, Reiner
A1 Stoehr, Robert
A1 Eckstein, Markus
A1 Bertz, Simone
A1 Wullich, Bernd
A1 Sikic, Danijel
A1 Wach, Sven
A1 Taubert, Helge
A1 Olbert, Peter
A1 Heers, Hendrik
A1 Lara, María Fernanda
A1 Macias, Maria Luisa
A1 Matas-Rico, Elisa
A1 Lozano, Maria José
A1 Prieto, Daniel
A1 Hierro, Isabel
A1 van Doeveren, Thomas
A1 Bieche, Ivan
A1 Masliah-Planchon, Julien
A1 Beaurepere, Romane
A1 Boormans, Joost L
A1 Allory, Yves
A1 Herrera-Imbroda, Bernardo
A1 Hartmann, Arndt
A1 Weyerer, Veronika
YR 2023
UL http://jcp.bmj.com/content/76/2/126.abstract
AB Aims Upper tract urothelial carcinoma (UTUC) is a rare malignancy with a poor prognosis which occurs sporadically or in few cases results from a genetic disorder called Lynch syndrome. Recently, examination of microsatellite instability (MSI) has gained importance as a biomarker: MSI tumours are associated with a better response to immunomodulative therapies. Limited data are known about the prevalence of MSI in UTUC. New detection methods using the fully automated Idylla MSI Assay facilitate analysis of increased patient numbers.Methods We investigated the frequency of MSI in a multi-institutional cohort of 243 consecutively collected UTUC samples using standard methodology (Bethesda panel), along with immunohistochemistry of mismatch repair (MMR) proteins. The same tumour cohort was retested using the Idylla MSI Assay by Biocartis.Results Using standard methodology, 230/243 tumours were detected as microsatellite stable (MSS), 4/243 tumours as MSI and 9/243 samples as invalid. In comparison, the Idylla MSI Assay identified four additional tumours as MSS, equalling 234/243 tumours; 4/243 were classified as MSI and only 5/243 cases as invalid. At the immunohistochemical level, MSI results were supported in all available cases with a loss in MMR proteins. The overall concordance between the standard and the Idylla MSI Assay was 98.35%. Time to result differed between 3 hours for Idylla MSI Assay and 2 days with the standard methodology.Conclusion Our data indicate a low incidence rate of MSI tumours in patients with UTUC. Furthermore, our findings highlight that Idylla MSI Assay can be applied as an alternative method of MSI analysis for UTUC.Data are available upon reasonable request.