Abstract 153P
Background
EGFR (Epidermal growth factor receptor) is a key driver mutation frequently isolated in lung cancers and anti-EGFR TKIs (tyrosine kinase inhibitors) have demonstrated significant improvements in patient outcomes in comparison to conventional chemotherapy. This study assessed the prevalence and clinical outcomes of EGFR mutations among Indian NSCLC cohort.
Methods
Retrospective analysis of 2548 NSCLC patients who underwent EGFR mutational analysis from 2013 to 2021 using amplified refractory mutation system (ARMS)/Scorpion® real time polymerase chain reaction. Clinical data for 141 patients was obtained and significance assessed using Kaplan-Meier and chi-square method.
Results
EGFR sensitizing mutations were detected in 40.4% (1029/2548) cases with compound mutations detected in 7.8% (81/1029) cases. EGFR mutations were detected at a higher prevalence in females (p = 0.002) and never-smokers (p < 0.001) in the cohort. Uncommon EGFR mutations demonstrated a locoregional variation with Exon 18 G719X (7.2%) been the most frequently isolated in comparison to TKI resistant exon 20 T790M (3.98%) in other NSCLC cohorts. Exon 20 Insertions (1.8%) which received approval for targeted therapies was observed in 19 cases. EGFR mutation demonstrated a significant relationship with regard to brain metastasis (p = 0.011). Patient follow-up and treatment response (mutational load) was monitored using ctDNA (liquid biopsy) on ddPCR platform. EGFR mutated individuals had significantly longer median overall survival compared to EGFR wild type (26 months vs 12 months, p −0.044).
Conclusions
The study provides significant insights into the molecular epidemiology of EGFR TKD mutational spectrum from India, reiterating its role as a key predictive marker in NSCLC. Mutational analysis of EGFR is a pre-requisite test employed to identify subcategories of patients who would benefit from the therapy in addition to identification of EGFR resistance in patients already on TKI therapy.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.