Tumor and immune environment changes in EGFR-TKI treated EGFR-mutant non-small cell lung cancer

Patients with EGFR mutations exhibit immunosuppressive microenvironments, limiting responsiveness to immunotherapy. In our analysis, 25 Korean patients diagnosed with NSCLC harboring common EGFR mutations (L858R and exon 19 microdeletion) that received EGFR-TKI treatment was compared before and after treatment. 25 patients were analyzed overall, and 14 patients were analyzed in the paired analysis who received first-line osimertinib. Among 171 ROIs, 68ROIs were used for tumor paired analysis, and 51 ROIs for immune region. In this study, clinical specimens from 25 patients were selected for spatial and whole transcriptome analysis. To decipher the molecular changes that occur with EGFR-TKI (especially, osimertinib) treatment, we conducted DEG analysis by categorizing the patients into pre-treated and post-treated groups. This study was approved by the Institutional Review Board of the Seoul National University Hospital and performed in accordance with the Declaration of Helsinki.