High Feasibility of Liquid-Based Cytological Samples for Detection of EGFR Mutations in Chinese Patients with NSCLC

Background: Activating mutations of epidermal growth factor receptor (EGFR) could predict response totyrosine kinase inhibitor (TKI) treatment in patients with non-small cell lung cancer (NSCLC). However, thedetection of EGFR mutation is frequently challenging in clinical practice for the lack of tumor tissue. The aim ofthis study was to investigate the feasibility of performing EGFR mutation testing on various types of liquid-basedcytology (LBC) samples. Materials and
Methods: A total of 434 liquid-based cytology samples were collectedfrom March 2010 and November 2013. Among them, 101 with diagnosis of lung adenocarcinoma had pairedsurgically resected specimens. The ADx Amplification Refractory Mutation System (ADx-ARMS) was used todetermine EGFR mutation status both in LBC and resected samples.
Results: All liquid-based cytology sampleswere adequate for EGFR mutation analysis. The mutation rate was 50.5% in the 434 NSCLC patients with LBCsamples and the incidence rates of EGFR mutation were consistent among different specimens. We also detectedEGFR positives in 52.5% (53/101) patients with paired histologic specimens. The concordance rate of EGFRmutation between LBC samples and paired histologic specimens was 92.1%.
Conclusions: Our results suggestthat liquid-based cytology samples are highly reliable for EGFR mutation testing in patients with NSCLC.