Evaluation of a Fully Automated Idylla Test System for Microsatellite Instability in Colorectal Cancer

Abstract Background Microsatellite instability (MSI) is a phenotype commonly observed in colorectal cancer, and is caused by a deficient mismatch repair (MMR) system. Determining MSI status greatly aids tumor prognosis and treatment plans in colorectal cancer, and plays a critical role in recent FDA-approved immunotherapies. As recognition of its importance grows, MSI has been identified in more types of cancers, underscoring the importance of accurate assays for determining MSI status in tumor cells. Currently, tumor MSI status is detected via Polymerase Chain Reaction (PCR)-based methods or immunohistochemistry (IHC). Methods In this study, we tested a new, fully automated MSI detection system (IdyllaTM MSI detection kit) released by Biocartis. We evaluated 42 FFPE tumor tissues, which were clinically tested for MSI status using PCR or IHC method, with the Idylla TM MSI detection system. Results The Idylla TM MSI detection system showed an overall 97.62% concordance rate with previously used methods. Moreover, this fully automated system requires less than five minutes “hands on” preparation time and 150 minutes total run time per sample. Conclusion The Biocartis Idylla TM MSI kit proves a powerful tool to accurately detect MSI status in tumor cells in a rapid and almost labor-free manner.