Prognostic Value of EGFR Exon-20 Insertions in Czech Patients With Advanced Non-small Cell Lung Cancer.

BACKGROUND/AIM Per literature, patients with epidermal growth factor receptor (EGFR) exon-20 insertions respond poorly to tyrosine kinase inhibitors (TKIs). This study analyzed real-world data to examine the prognostic and predictive value of these mutations. PATIENTS AND METHODS We conducted a retrospective cohort study using Czech TULUNG Registry data, with data on multiple mutation types, collected in 2011-2020. RESULTS We analyzed 554 (95.85%) patients with EGFR exon-19 deletions or exon-21 L858R substitutions and 24 (4.15%) patients with exon-20 insertions who received first-line high-value therapies. We summarized clinical characteristics and outcomes in all patients and by cohort. The risk of progression was statistically significantly higher (86%) in the exon-20 insertion cohort compared to the cohort with other mutations. Although not statistically significant, the risk of death was 44% higher in patients with exon-20 insertions. CONCLUSION Advanced NSCLC patients with rare EGFR exon-20 insertions have a high risk of progression.