Molecular Testing for EGFR Mutation in Moroccan NSCLC Patients: CHU Hassan II-Fez Experience

Abstract

Epidermal growth factor receptor ( EGFR) mutation screening in non-small cell lung cancer (NSCLC) is now used to guide treatment decisions to identify patients with EGFR positive mutations that predict response to EGFR tyrosine kinase inhibitors. This study aimed to explore with a prospective study the current testing practices and the predictive value of EGFR mutations in a series of 261 patients with NSCLC. EGFR mutation testing was conducted using 2 different assays: bidirectional Sanger sequencing of polymerase chain reaction (PCR) and real-time PCR on the Rotor-Gene Q instrument. Epidermal growth factor receptor mutation testing was performed for 261 patients with lung cancer. Exons 18 to 21 were successfully analyzed in 113 tumors by Direct sequencing and in 148 tumors by real-time PCR. The prevalence of positive EGFR-mutations in each method was 22.1% (N = 25) and 24.3% (N = 36), respectively ( P = .3). In total, EGFR mutations were detected in 59 patients among 261 patients with NSCLC. A statistically significant association between female sex, nonsmoking history, nonsolid major pattern, and a higher EGFR mutation frequency. In this study, we investigated clinicopathological differences between tumors harboring exon 19del and those harboring L858R. We did not find any significant differences between the 2 mutations and gender or smoking features, interestingly, the prevalence of patients aged >60 years was significantly higher in the L858R group than in the exon 19del group (81.8% vs 55.8%, P = .05). A significant association was observed between exon 19 deletions and the papillary major pattern, but no correlation was detected between exon 21 mutation and any histological pattern. This prospective study documented the real-world clinical testing of EGFR mutation in Moroccan NSCLC patients. Our experience confirms the need to develop standards-based guidelines for the routine performance and evaluation of EGFR testing to improve clinical care for this subset of lung cancer. On the other hand, our study demonstrated that tumors with exon 19 deletions and L858R harbor specific clinicopathological features in NSCLC.