59P - Correlation of tumor microenvironment signature in advanced stage non-small cell lung cancer with EGFR mutation who received EGFR-TKIs

Background

The impact of tumor microenvironment in advanced non-small cell lung cancer (NSCLC) who had epidermal growth factor receptor (EGFR) mutation remained debated. We investigated the correlation of tumor microenvironment (PD-L1, CD8 and FOXP3) and the association of EGFR TKI treatment outcome.

Methods

A prospective study was conducted to recruit 100 participants who were diagnosed advanced NSCLC with EGFR mutation. All patients were received treatment with EGFR-tyrosine kinase inhibitors (TKIs). Tumor microenvironment composed of programmed cell death ligand-1 (PD-L1) expression, CD8+ tumor infiltrating lymphocyte (TILs) and forkhead box P3 (FOXP3+) TILs density were evaluated by immunohistochemistry. The primary endpoint was the correlation between PD-L1, CD8+, and FOXP3+ TILs density. The Correlations among TILs and clinicopathological characteristics/outcome of treatment were analyzed.

Results

Eighty-five patients with adequate tumor material were evaluated. Twelve (14%) patients expressed high PD-L1 (≥15%) or intratumoral CD8+ TILs (>10%). The correlation of PD-L1 and intratumoral CD8+ TILs was significantly (r = 0.3034, p=0.005). Multivariate analysis revealed that Inflamed tumor was correlated with shorten PFS with the HR of 2.110, 95%CI: 0.968-4.599, p-value 0.06.

Conclusions

Among advanced stage NSCLC with EGFR mutation, tumor microenvironment PD-L1 and intratumoral CD8+ TILs expression was correlated with outcome of treatment.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Health Systems Research Institute of Thailand.

Disclosure

All authors have declared no conflicts of interest.