Evaluation of Two EGFR Mutation Tests on Tumor and Plasma from Patients with Non-Small Cell Lung Cancer

• Published in: Cancers Vol. 12; no. 4; p. 785
• Main Authors: Kim, Jeong-Oh, Shin, Jung-Young, Kim, Seo Ree, Shin, Kab Soo, Kim, Joori, Kim, Min-Young, Lee, Mi-Ran, Kim, Yonggoo, Kim, Myungshin, Hong, Sook Hee, Kang, Jin Hyoung
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 26.03.2020; MDPI AG
• Subjects: Brief Report; circulating free dna; epidermal growth factor receptor; liquid biopsy; osimertinib; tyrosine kinase inhibitor; tyrosine kinase inhibitor; epidermal growth factor receptor; liquid biopsy; circulating free DNA; osimertinib
• ISSN: 2072-6694; 2072-6694
• DOI: 10.3390/cancers12040785

Epidermal growth factor receptor ( ) mutation testing is essential for individualized treatment using tyrosine kinase inhibitors. We evaluated two mutation tests, cobas v2 and PANAMutyper, for detection of activating mutations Ex19del, L858R, and T790M in tumor tissue and plasma from 244 non-small cell lung cancer (NSCLC) patients. The Kappa coefficient (95% CI) between the tests was 0.82 (0.74-0.92) in tumor samples (suggesting almost perfect agreement) and 0.69 (0.54-0.84) in plasma (suggesting substantial agreement). In plasma samples, both tests showed low to moderate sensitivity depending on disease stage but high diagnostic precision (86%-100%) in all disease stages (sensitivity: percentage of mutations in tumors that are also detected in plasma; precision: percentage of mutations in plasma which are also detected in tumors). Among the 244 patients, those previously diagnosed as T790M carriers who received osimertinib treatment showed dramatically better clinical outcomes than T790M carriers without osimertinib treatment. Taken together, our study supports interchangeable use of cobas v2 and PANAMutyper in tumor and plasma testing. Both tests have high diagnostic precision in plasma but are particularly valuable in late-stage disease. Our clinical data in T790M carriers strongly support the clinical benefits of osimertinib treatment guided by both mutation tests.