J Cancer Res Ther. 2026 Apr 1;22(3):525-530. doi: 10.4103/jcrt.jcrt_1710_25. Epub 2026 Aug 14.
ABSTRACT
BACKGROUND: Non-Small Cell Lung Carcinoma (NSCLC) is frequently associated with driver mutations in the epidermal growth factor receptor (EGFR) gene. Activating EGFR mutations occur in approximately 14-38% of NSCLC cases, with common mutations-exon 19 deletions and exon 21 L858R-accounting for nearly 90%. Uncommon mutations, including G719X, S768I, L861Q, and exon 20 insertions (Ins20), excluding T790M, comprise about 10-15% and are increasingly recognized for their therapeutic implications.
METHODS: This retrospective study profiled uncommon EGFR mutations in NSCLC patients at a tertiary cancer care center. EGFR mutation testing was performed on 4463 samples using a commercial detection kit. Statistical analyses were conducted using Python 3, with P < 0.05 considered significant.
RESULTS: EGFR mutations were identified in 32.2% (1441/4463) of cases, of which 85.37% were common and 9.92% were uncommon (excluding T790M). Among uncommon mutations, 77.7% were single and 22.2% were compound. The most frequent single mutation was Ins20 (27%), followed by L861Q (25.7%) and G719X (20.8%). These mutations were most common in patients aged 51-70 years, predominantly with adenocarcinoma histology. Nodal staging was available for 118 patients, while both nodal and treatment data were available for 112. No significant association was observed between mutation subtype and nodal staging (P = 0.918). However, a significant correlation was found between mutation subtype, distant metastasis, and treatment modality (P < 0.001).
CONCLUSIONS: Uncommon EGFR mutations in NSCLC are associated with advanced-stage presentation. While nodal staging is independent of mutation subtype, treatment strategies are strongly genotype-driven, underscoring the importance of precise molecular characterization.
PMID:42617018 | DOI:10.4103/jcrt.jcrt_1710_25
