Objective: To investigate the sensitivity of bi-loop probe and specific primer quantitative PCR (BPSP-qPCR) in the detection of epidermal growth factor receptor (EGFR) gene mutations in non-small cell lung cancer (NSCLC).
Methods: BPSP-qPCR was employed to examine the presence of mutations of EFGR exon 19 through 21. Correlation of the mutations with clinicopathological characteristics and types of tumor samples were performed.
Results: In the cohort of 265 specimens, 30.2% (80/265) mutations were found to be 19-del and/or L858R. Females (39.7%, 31/78), non-smokers (41.0%, 43/105) and adenocarcinoma patients (37.8%, 51/135) had a higher mutation rate (P<0.05) among 184 patients whose profiles were available. T790M combined with 19-del and/or L858R accounted for 3.3% (6/184) of the mutations. Male metastatic tumors (29.6%, 8/27), pleural fluids of females (42.9%, 9/21) and non-smokers (40.7%, 11/27) were found to have higher percentage of 19-del and/or L858R mutations, in contrast, no mutations were found in the metastatic lesions of non-adenocarcinoma patients (P>0.05).
Conclusions: BPSP-qPCR is a robust method in detection of EGFR mutations with high consistency and sensitivity. The difference of EGFR mutations in primary tumors, metastatic lesions and pleural fluids suggests that EGFR tyrosine kinase inhibitors (EGFR-TKI) treatment may have variable treatment effects depending on the tumor sites.