Abstract

Exons 18-21 of the EGFR gene are frequently mutated in NSCLC, often showing favorable responses to TKIs. However, rare EGFR mutations, such as those occurring in exon 7, remain underexplored. This study reports four NSCLC cases with uncommon exon 7 mutations identified via NGS. Three potentially pathogenic variants (c.866C>T, p.A289V; c.866C>A, p.A289D) and two variants of uncertain significance were detected. Among these, one patient who received TKI therapy exhibited early disease progression. Additionally, our patient sample displayed unusual clinical and pathological characteristics, differing from those typically associated with common EGFR mutations. These findings underscore the need for further research into the clinical implications and therapeutic strategies for rare EGFR mutations.

Keywords: Squamous cell; Chemo-radiotherapy; Clinical and pathological; Next-generation sequencing (NGS) and Lung cancer