Liquid biopsy has been adapted as a diagnostic test for EGFR mutations in patients with advanced or metastatic non-small cell lung cancer (NSCLC). Loop-mediated isothermal amplification (LAMP) has been widely used for the rapid detection of pathogens through DNA amplification. This study investigated the efficacy of an EGFR-LAMP assay using plasma samples of patients with resected NSCLC tumors. The EGFR status was investigated using both LAMP and next-generation sequencing (NGS) assays in cases that met the following criteria: (1) pulmonary adenocarcinoma with EGFR mutation detected by the Therascreen EGFR PCR Kit and (2) preoperative plasma samples contained enough DNA for the LAMP and NGS experiments. Among 51 specimens from patients with EGFR-mutated tumors or metastatic lymph nodes, the LAMP assay detected 1 EGFR mutation that was also detected in the NGS assay. However, a plasma sample that demonstrated EGFR wild type in the LAMP assay showed an EGFR mutant status in NGS. The detection rates (1.9% in LAMP and 3.9% in NGS) were very low in both assays, demonstrating a similar performance in detecting EGFR mutations in NSCLC tumors; therefore, it could be a more suitable test for the advanced stage, not the early stage. Notably, the LAMP assay was more time-saving, cost-effective, and straightforward. However, further investigation is required to develop a more sensitive assay.
Keywords: epidermal growth factor receptor; liquid biopsy; loop-mediated isothermal amplification; lung cancer; point-of-care testing; polymerase chain reaction.