A novel ARMS-based assay for the quantification of EGFR mutations in patients with lung adenocarcinoma

Abstract

Quantification of epidermal growth factor receptor (EGFR) mutations is important for the prediction of tyrosine kinase inhibitor (TKI) efficacy in patients with non-small cell lung cancer (NSCLC). However, clinicians lack a sensitive and convenient method to quantify EGFR mutant abundance. The present study introduces a novel method, namely amplification refractory mutation system (ARMS)-Plus, for the quantitative analysis of EGFR exon 19 deletion (19Del), L858R and T790M mutations. Formalin-fixed paraffin-embedded tumor samples were collected from 77 patients with lung adenocarcinoma. DNA was extracted and analyzed for EGFR mutations using ARMS-Plus. The performance of ARMS-Plus was then compared with that of conventional ARMS-polymerase chain reaction (ARMS-PCR) and droplet digital PCR (ddPCR). The results demonstrated that the concordance rate of EGFR mutation testing between ARMS-Plus and ddPCR was 98.7% (76/77, Kappa=0.9739). 19Del and L858R mutations were detected in 23 and 12 patients, respectively. There was a significant difference between ARMS-Plus and ddPCR in the evaluation of 19Del mutant abundance (P=0.0002); however, not in that of L858R mutant abundance (P=0.7334). The ARMS-Plus results in L858R mutant abundance were concordant with that of ddPCR (R2=0.8081). These results indicated that the sensitivity and specificity of ARMS-Plus in identifying EGFR mutations were similar to that of ddPCR. For quantitative analysis, the results of ARMS-Plus in evaluating L858R mutant abundance revealed a positive correlation with the ddPCR results. Thus, ARMS-Plus provides an alternative method, which is reliable and cost-effective, to quantify EGFR mutations and thereby, aid treatment decisions in patients with lung adenocarcinoma.