Comparison of ARMS and direct sequencing for detection of EGFR mutation and prediction of EGFR-TKI efficacy between surgery and biopsy tumor tissues in NSCLC patients

The relationship between epidermal growth factor receptor (EGFR) mutation status and EGFR-tyrosine kinase inhibitors (TKI) efficacy in non-small cell lung cancer (NSCLC) patients has been well established. However, there is no available standard to define the optimal testing method and specimen type required for the detection of EGFR mutations. In this study, we compare results of ADx-amplification refractory mutation system (ARMS) and direct sequencing for the detection of EGFR mutation and prediction of EGFR-TKI efficacy for surgery and biopsy tumor tissues in 158 NSCLC patients. For 71 surgery samples, there were 13 and 17 positive samples detected by direct sequencing and ARMS, respectively. For 87 biopsy samples, direct sequencing and ADx-ARMS found 15 and 32 positive samples, respectively. For surgery samples, sensitivity of direct sequencing and ARMS was 72.2 % (13/18) and 94.4 % (17/18), respectively. For the biopsy samples, sensitivity of direct sequencing and ARMS was 44.1 % (15/34) and 94.1 % (32/34), respectively. For the biopsy and surgery samples, the ORRs for EGFR positive and negative patients detected by direct sequencing were 46.1 versus 16.7 and 66.7 versus 1.1 %, respectively. For ADx-ARMS, the ORR for EGFR positive patients was significantly higher than for negative patients (55.6 vs. 5.6 %). The median progression-free survival time of patients with EGFR wild type detected by direct sequencing (4.2 months) was significantly longer than that of patients with wild type detected by ARMS (1.7 months). ARMS has a higher sensitivity and specificity than direct sequencing for EGFR detection of mutation in both surgical and biopsy samples, and the results from ARMS are more consistent with the efficacy of EGFR-TKIs treatment.