Application of IdyllaTM System for Rapid Evaluation of EGFR Mutation Status in Formalin-Fixed and Paraffin-Embedded Samples of Non-Small Cell Lung Cancer.

Objective: In approximately 80% of the patients with advanced non-small cell lung cancer (NSCLC), the only samples available are cytological material or a limited amount of tissue specimens. Therefore, we aimed to explore the effect of the Idylla™ system for rapid evaluation of epidermal growth factor receptor (EGFR) mutation status in formalin-fixed and paraffin-embedded (FFPE) samples of NSCLC patients.

Methods: A total of 221 archived FFPE NSCLC tissue specimens were included in this study. Idylla™ system and amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) were used to detect the EGFR mutation status. The Idylla™ system results and ARMS-PCR results were compared. When results were discordant, the Idylla™ system would be retested, and a third analysis method was performed to confirm test results when possible.

Results: Among the 220 valid results of the Idylla™ system, the Idylla™ identified EGFR mutations in 109 cases with an incidence of mutation of 49.55%. The Idylla™ assay results were in complete agreement with the results of the reference methods for 207 cases, yielding an overall accordance of 94.09% (207/220, 95% CI, 90.11%-96.82%). Consequently, the overall concordance with routine reference methods, including further analysis, was found to be 96.81% (213/220, 95% CI: 93.28%-98.60%), with a negative percentage agreement of 97.3% (108/111, 95% CI: 91.72%-99.30%) and a positive percentage agreement of 96.33% (105/109, 95% CI: 90.32%-98.81%).

Conclusion: The Idylla™ system is a rapid and effective method that enables sensitive and reliable detection of EGFR mutations in FFPE samples of NSCLC patients, with minimal molecular expertise or infrastructure.