A Comparison of Direct Sequencing and ARMS Assay Performance in EGFR Mutation Analysis of Non-small Cell Lung Cancer Patients

Abstract

Background and objective Epidermal growth factor receptor (EGFR) inhibitors are mainly used for the targeted therapy of non-small cell lung cancer (NSCLC). Therefore, EGFR mutations should be detected to treat lung cancer. The aim of this study is to determine the detection rate of NSCLC in patients with EGFR gene mutations by conducting direct sequencing and ARMS assay. Methods A total of 451 patients who were diagnosed with NSCLC between April 2012 and June 2013 participated in this study. Gene mutation was detected in the exon of EGFR 18 to 21 by direct sequencing and ARMS assay. Results All of the 451 cases of NSCLC were subjected to direct sequencing and ARMS assay. Using both techniques, we detected the same EGFR mutation in 127 cases and different EGFR mutations in 5 cases, but no mutations were detected in 186 cases. In direct sequencing alone, EGFR mutation was detected in 50 cases. In ARMS assay alone, EGFR mutation was detected in 83 cases. The mutation rates of direct sequencing and ARMS assay were 40.4% and 47.7%, respectively. Therefore, the mutation detection rate of ARMS assay was significantly higher than that of direct sequencing (P<0.001). In 204 paraffin tissue samples of NSCLC, the mutation detection rate of ARMS assay (59.80%) was significantly higher than that of direct sequencing (41.67%; P<0.001). By comparison, the mutation detection rates of ARMS assay (39.58%) and direct sequencing (38.33%) showed no significant difference (P=0.083) when 240 fresh tissue samples of NSCLC were used. Conclusion Direct sequencing and ARMS assay exhibited similar efficacy in detecting EGFR mutations. Despite its high operational costs, ARMS assay was more sensitive and more convenient than direct sequencing, particularly when a small number of tissues were used. By comparison, direct sequencing could detect mutations that were not detected by ARMS assay. Therefore, the combination of direct sequencing and ARMS assay could provide more reliable and comprehensive test results than the lone application of each technique.

Keywords

• EGFR mutation
• Direct sequencing
• ARMS
• Lung neoplasms