Microfluidics-based EGFR mutation detection and its implication in the resource-limited clinical setting.

Abstract

Management of lung cancer today obligates a mutational analysis of the epidermal growth factor receptor (EGFR) gene particularly when Tyrosine Kinase Inhibitor (TKI) therapy is being considered as part of prognostic stratification. This study evaluates the performance of automated microfluidics-based EGFR mutation detection and its significance in clinical diagnostic settings. Formalin-fixed, paraffin-embedded (FFPE) samples from NSCLC patients (n = 174) were included in a two-phase study. Phase I: Validation of the platform by comparing the results with conventional real-time PCR and next-generation sequencing (NGS) platform. Phase II: EGFR mutation detection on microfluidics-based platform as part of routine diagnostics workup. The microfluidics-based platform demonstrates 96.5% and 89.2% concordance with conventional real-time PCR and NGS, respectively. The system efficiently detects mutations across the EGFR gene with 88.23% sensitivity and 100% specificity. Out of 144 samples analysed in phase II, the platform generated valid results in 94% with mutation detected in 41% of samples. This microfluidics-based platform can detect as low as 5% mutant allele fractions from the FFPE samples. Therefore the microfluidics-based platform is a rapid, complete walkaway, with minimum tissue requirement (two sections of 5 μ thickness) and technical skill requirement. The method can detect clinically actionable EGFR mutations efficiently and can be considered a reliable diagnostic platform in resource-limited settings. From receiving samples to reporting the results this platform provides accurate data without much manual intervention. The study helped to devise an algorithm that emphasizes effective screening of the NSCLC cases for EGFR mutations with varying tumour content. Thus it helps in triaging the cases judiciously before proceeding with multigene testing.