Clinical performance evaluation of a sensitive, rapid low-throughput test for KRAS mutation analysis using formalin-fixed, paraffin-embedded tissue samples

Testing for KRAS mutations in metastatic colorectal cancer (mCRC) on formalin-fixed, paraffin embedded (FFPE) tumor tissue has become standard of care. Different molecular methods exist to determine hotspot KRAS mutations in exon 2, 3 and 4, but testing is often limited by the sensitivity and the speed of analysis. The aim of this retrospective study was to establish the clinical performance of the Idylla™ KRAS Mutation Test on FFPE tumor samples of patients with mCRC. KRAS mutation analysis was performed using the therascreen KRAS on the RotorGene Q platform (CE-IVD; Qiagen) and results were subsequently compared to the Idylla™ KRAS Mutation Test. Discordant result testing was performed with massive parallel sequencing or alternative routine approaches. Data from 182 samples were used to show that the overall agreement between the two methods for mutation characterization was 96.7% [95%CI: 93.0%-98.5%]. Six out of 182 samples (3.3%) showed true discordant results. The Idylla™ KRAS Mutation Test allows for a fast and reliable analysis of FFPE samples with a turnaround-time of two hours without the need of molecular infrastructure or expertise in order to guide the personalized treatment of colorectal cancer patients.