EGFR L747-S752 del

Here, we reported a NSCLC patient harboring both METex14skipping and METamp that led to effective second-line treatment with capmatinib after progression on osimertinib. Molecular profiling was performed using a 50-gene hotspot next-generation sequencing (NGS) panel called APEX, which sequences both DNA and RNA molecules. This case represents a unique case of oncogenic addiction to the MET pathway in the metastatic tumor identified with the co-occurrence of METamp and METex14skipping (the latter indicative of the emergence of a new clone). It also underscores the importance of repeat molecular profiling of the metastatic tumor tissue using a broad NGS panel in identifying potential actionable biomarkers to guide treatment selection after disease progression on first-line EGFR-TKI.

NSCLC with EGFR 19Del/Delins should not be considered as a homogenous disease. NSCLC with uncommon EGFR 19Del/Delins displayed a more active adaptive immunity in tumor microenvironment, which indicated the potential vulnerability of immunotherapy.

She was treated with gefitinib, an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) because of EGFR mutation (L747-S752 del). This TP53 mutation (R333Vfs*12) was first found in lung adenocarcinomas. The therapeutic effect of osimertinib for this triple mutant lung adenocarcinoma is better than the previous report.