Efficacy of EGFR tyrosine kinase inhibitors in patients with EGFR-mutated non-small cell lung cancer except both exon 19 deletion and exon 21 L858R: A retrospective analysis in Korea

These results suggest that rare or complex EGFR mutations confer inferior response and survival to the EGFR-TKI treatment compared to common mutations. Further studies using larger numbers of patients are needed to determine better subclassifications for these patients.