Detection of EGFR mutation in plasma using multiplex allele-specific PCR (MAS-PCR) and surface enhanced Raman spectroscopy

In this study, surface enhanced Raman spectroscopy (SERS) in combination with multiplexed polymerase chain reaction (PCR) was utilized to detect mutations of exons 19 and 21 of the epidermal growth factor receptor (EGFR) gene. Through the use of multiplexed PCR, the two mutation types were amplified in a single reaction. SERS was used on the PCR products to detect mutations. DNA mixtures with increasing mutation percentages showed good linear relationship between mutation rates and peak height. Then, this PCR-SERS method was used on the plasma of 48 patients with non-small cell lung cancer (NSCLC) to detect EGFR mutations. Analysis of variance (ANOVA) and receiver operating characteristic (ROC) analysis revealed that the peak height ratios were significant for identifying different mutation types. The specificity, sensitivity and accuracy obtained were all 100%. The proposed method was then validated through comparison with high resolution melting (HRM) and showed high concordance with HRM (Pearson correlation is 0.92). Finally, logistic regression was performed on EGFR mutation status and the clinical features of the 48 patients. Our study indicates that PCR-SERS is an effective, noninvasive, and economical method for the detection and monitoring of EGFR mutations in the plasma of patients with NSCLC.