Advanced Non-small Cell Lung Cancer: EGFR Mutation Analysis Using Pyrosequencing and the Fully Automated qPCR-Based Idylla^TM System

Background: Epidermal growth factor receptor (EGFR) mutation status is of a major clinical significance in non-small cell lung cancer (NSCLC) management, as it guides therapeutic decision making to target patients for a better response to therapy. This implicates the introduction of EGFR mutation analysis as the standard of care for Moroccan NSCLC patients, which in itself entails the implementation of targeted methods for routine EGFR mutation analysis in our laboratories. In this study, we aimed to present 2 targeted methods for EGFR mutation identification and to determine the prevalence and spectrum of EGFR mutations in NSCLC Moroccan patients. Methods: A retrospective investigation of a cohort of 340 patients was undertaken to analyze somatic EGFR mutations in exons 18 to 21 using pyrosequencing and the IdyllaTM system. Results: Of the enrolled patients, 70.9% were males and 29.1% were females. Predominately, 92% of cases had adenocarcinoma, and 53.7% of patients self-reported a history of smoking. Overall, 73 patients (21.7%) harbored an EGFR mutation, the most prevalent of which were the exon 19 deletions (53.4%) followed by exon 21 substitutions (31%). Exon 18 mutations and exon 20 alterations occurred in 8.1% and 6.7% of the positive EGFR mutation cases, respectively. Of the analyzed cases, all of the EGFR-mutated patients had adenocarcinoma. EGFR mutation prevalence was significantly higher in females (females vs males: 38.4% vs 14.5%, P <.001) and non-smokers (non-smokers vs non-smokers: 36% vs 10.3%, P <.001). The featured pyrosequencing and the IdyllaTM system are targeted methods endowed with high sensitivity and specificity as well as other compelling characteristics which make them great options for routine EGFR mutation testing for advanced NSCLC patients. Conclusion: These findings underline the imperious need for implementing quick and efficient targeted methods for routine EGFR mutation testing among NSCLC patients, which is particularly useful in determining patients who are more likely to benefit from targeted therapy.