EGFR detection by liquid biopsy: ripe for clinical usage

Area of Science:

• Oncology
• Molecular Diagnostics
• Genetics

Background:

• Liquid biopsy is increasingly recommended for lung cancer detection by the International Association for the Study of Lung Cancer (IASLC).
• Accurate genotyping of plasma samples is crucial for guiding targeted therapy in non-small cell lung cancer (NSCLC).

Purpose of the Study:

• To evaluate the concordance of different plasma genotyping platforms against tissue biopsy as the gold standard.
• To assess the diagnostic performance of Cobas, droplet digital polymerase chain reaction (ddPCR), and Therascreen assays for epidermal growth factor receptor (EGFR) mutations in NSCLC.

Main Methods:

• 184 NSCLC patients underwent EGFR genotyping using Cobas, ddPCR, and Therascreen assays.
• Data collected between 2019-2020.
• Concordance and sensitivity were analyzed, including receiver operating characteristic (ROC) analysis.

Main Results:

• Cobas detected mutations in 70 cases, ddPCR in 51, and Therascreen in 69 out of 184 patients.
• Cobas exhibited a sensitivity of 97.1%, while ddPCR showed 71% sensitivity.
• ROC analysis indicated an area under the curve (AUC) of 0.977 for Cobas and 0.846 for ddPCR.

Conclusions:

• Cobas demonstrated superior performance compared to ddPCR for EGFR genotyping in NSCLC patients.
• Understanding the performance characteristics of these liquid biopsy platforms is essential for selecting appropriate diagnostic tests.
• Accurate genotyping supports timely initiation of targeted therapies like osimertinib, aligning with clinical trial findings and guidelines.