Evaluation of the Idylla™ EGFR Mutation Test on formalin-fixed, paraffin-embedded tissue of human lung cancer.

Abstract

Epidermal growth factor receptor (EGFR) mutation detection is essential for the therapy of lung cancer. A sensitive, specific, and cost-effective standardized method to quickly and accurately detect EGFR mutations is urgently needed. We evaluated the Idylla™ EGFR Mutation Assay for EGFR mutations in formalin-fixed, paraffin-embedded (FFPE) tumor samples from 232 lung cancer patients, and compared the results with amplification refractory mutation system (ARMS) (n=146) and next-generation sequencing (NGS) (n=86). The surgical tumor sections and cell blocks derived from the same FFPE section were compared. Overall concordance, specificity, sensitivity, cost-effectiveness and turnaround time were compared among the three methods. The overall concordance between Idylla and ARMS was 89.51% [95% confidence interval (CI): 83.31% to 93.64%] and the specificity of Idylla was 88.68% (95% CI: 80.69% to 93.76%). A concordance of 97.67% (95% CI: 91.41% to 99.86%) was obtained between Idylla and NGS, the specificity of Idylla was 96.30% (95% CI: 86.16% to 99.36%). Compared to the ARMS and NGS, the Idylla™ system significantly reduces the turnaround time. Combining labor, equipment, reagents and time costs, Idylla is more affordable. Clinically urgent cases with adequate cellularity, can first perform Idylla to detect critical markers, then perform NGS for a comprehensive mutation analysis. Besides, with limited molecular expertise or infrastructure, the Idylla has the potential to extend EGFR testing to more pathology laboratories in primary hospitals.