Evaluation of molecular methods for plasma detection of EGFR mutations in non‐small cell lung cancer

• Published in: Asia-Pacific journal of clinical oncology 2022-12, Vol.18 (6), p.595-604
• Main Authors: Lee, Kyunghoon, Lim, Sangeun, Lee, Yun‐Gyoo, Kim, Haejeung, Lee, Seungjun, Yu, Hui‐Jin, Park, Hyosoon, Kwon, Min‐Jung, Woo, Hee‐Yeon
• Format: Article
• Language: English
• Subjects: Body fluids; Carcinoma, Non-Small-Cell Lung - drug therapy; Carcinoma, Non-Small-Cell Lung - genetics; digital PCR; EGFR; Epidermal growth factor; Epidermal growth factor receptors; ErbB Receptors - genetics; Gene frequency; Humans; Lung cancer; Lung Neoplasms - drug therapy; Lung Neoplasms - genetics; Mutation; Non-small cell lung carcinoma; NSCLC; Plasma; Protein Kinase Inhibitors - therapeutic use; Protein-tyrosine kinase; Real-Time Polymerase Chain Reaction; real‐time PCR; Small cell lung carcinoma
• ISSN: 1743-7555; 1743-7563
• DOI: 10.1111/ajco.13705

Aim Epidermal growth factor receptor (EGFR) mutations are detected in non‐small cell lung cancer (NSCLC) and associated with responses to therapy with tyrosine kinase inhibitors (TKIs). We compared the analytical performances of two real‐time PCRs and droplet digital PCR (ddPCR) to detect EGFR mutations using plasma. Methods Plasma EGFR tests were performed using 86 plasma samples from 75 prospectively enrolled NSCLC patients with early and advanced stages. Analytical performances of plasma‐using two real‐time PCR, Cobas EGFR mutation v2 and PANAMutyper, EGFR kit, and ddPCR were evaluated based on the tissue EGFR test results. The frequencies of EGFR mutations and acquired T790M mutation after TKI therapy were also assessed. Results The incidence of all EGFR mutations was 52.3% (23/44) in tissue and was up to 43.2% (19/44) in plasma. The Cobas detection rates of three EGFR mutations (exon 19 deletions, L858R, and T790M) in plasma were similar to those in tissue. The Cobas showed a higher detection rate (76.7%) than that by the PANAMutyper (60.5%). Sensitivity for T790M mutation was lower than the sensitivity for the exon 19 deletions or L858R in both tests. Mutant allele frequency measured by ddPCR was significantly correlated with the semi‐quantitative values of the Cobas. Conclusions Plasma EGFR tests showed similar detection rates for common EGFR mutations compared to the tissue EGFR tests. Cobas showed higher sensitivity in detection of EGFR mutations in body fluids than the PANAMutyper. Real‐time PCR using plasma or body fluids could be a suitable first test for the detection of EGFR mutations.