The information on EGFR mutations status improves the benefit of targeted therapies for the non-small-cell lung cancer patients. These determinations are already part of standard protocols for cancer treatment. The study of the mutations in EGFR in liquid biopsy also permits a follow-up throughout the treatment and detection of acquired resistance.
CLART® CMA EGFR kit (GENOMICA, Spain) detects the 40 high-prevalence mutations associated with sensitivity or resistance to the treatment. These mutations are located in the exons 18, 19, 20 and 21. The kit is based on the multiplex ARMS-PCR followed by detection on a low-density microarray platform: CLART® (Clinical Arrays Technology). The samples were processed in a bench-top semi-automated system, Autoclart. A new version of the kit, CLART® CMA EGFR LB, allows using liquid biopsy as a sample with only an additional pre-PCR step.
A 107 tissue biopsies from metastatic NSCLC patients were obtained and analyzed in two University Hospitals in Spain: Vall d’Hebron (Barcelona) and 12 de Octubre (Madrid). The EGFR mutations were detected with CLART® CMA EGFR kit with 96.3% concordance with the routine methods used in the hospital practice (Cobas/Therascreen/Sanger sequencing). The discrepant results were analyzed by Sanger sequencing. The sensitivity of the CLART® CMA EGFR kit is 100% and specificity is 96.5%. The same CLART platform, only with the addition of one pre-PCR amplification step was used for processing the plasma samples (liquid biopsy) from the NSCLC metastatic patients. A total of 8 samples were tested. In six samples the results obtained from tissue samples and liquid biopsies were concordant. In the two discordant samples the exon 19 deletions detected in tissue were not detected in plasma samples. The wt results obtained for these two liquid biopsies were confirmed by Next Generation Sequencing.
Given the high specificity and sensitivity and excellent concordance with the other platforms in hospital practice, CLART® CMA EGFR kit is valid for the use in the clinical routine. Furthermore, using the same semi-automated platform for tissue samples and liquid biopsy facilitates laboratory work and reduces turnover time per sample.
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All authors have declared no conflicts of interest.