8 Statut mutationnel du gène EGFR dans le cancer bronchique non-à-petites cellules : comparaison entre tumeurs primitives et métastases

Abstract

The study of EGFR gene mutational profile in NSCLC patients has a special clinical significance in the selection of patients for tyrosine-kinase inhibitors therapy. From 2017, the targeted therapy started to be accessible in public sector in Morocco, thus, the implementation of techniques for the molecular characterization of EGFR mutations in the laboratories became a necessity. The aim of this study was to present targeted methods “ADx-ARMS technology and the Idylla™ system” for the identification of EGFR mutational profile, methods that can be implemented in our clinical laboratories for routine analysis instead of outsourcing analysis to other countries. We conducted this study by processing 239 cases of NSCLC patients. Using the DNA extracted from the FFPE tissue, we evaluated somatic mutations in exons 18 to 21 of the tyrosine-kinase domain of EGFR gene by HRM-PCR combined to real time PCR “ADx-ARMS technology” and Idylla™ system. These sensitive methods showed that among the positive mutant cases, the distribution of mutations was as follows: 70% of patients having a deletion in exon 19, 15% in exon 21 (L858R), 7.5% in exon 20 and 7.5% in exon 18 (G719X). All of the positive EGFR mutations cases were adenocarcinoma and 42.1% of them were smokers. These results show the need to incorporate a quick and efficient method for the identification of EGFR mutation into routine practice in our laboratories, allowing more patients to benefit from targeted therapy.