189P The parallel interrogation of tissue and peripheral blood immune features unveils a bidirectional crosstalk with clinical impact on resected NSCLC

The cancer-immune interplay and its role on the evolution of NSCLC might be disclosed through detection local systemic cues. Aim: To determine whether peripheral blood (PB) immune profiles may mirror clinically relevant tumor microenvironmental (TIME) features in resected patients. Tissue PB samples were prospectively collected at surgery from 80 consecutive stage I-IIIA cases. immunohistochemical evaluation TIME involved PD-L1 status spatial distribution CD3+, CD4+, CD8+, PD1+ Tumor Infiltrating Lymphocytes (TILs), defined as efficient (IEff) when contact with cancer cells or excluded (IEx) trapped fibrosis. TILs clustering was also considered. CD4+ CD8+ lymphocytes, NKs, Tregs together expression PD1, Granzyme B (GnZ) Perforin (Perf) assessed by flowcytometry. TIME-PB relationships their clinico-pathological correlates statistically examined. Compared to II III, I revealed increased CD3, CD8 CD4 clusters (P = 0.03) coupled higher lymphocytes 0.02). Females displayed greater IEff clustered CD3 CD4, while males exhibited more distally located predominant GnZ+ <0.05). Blood PD-L1pos showed a significant switch favoring 0.007), PD-L1neg cases presented 0.02) 0.05) phenotype. CD4-to-CD8 ratio density directly correlated CD4/CD8 0.002) number 0.05), whereas an opposite trend between detected. PD1-to-CD8 inversely related fraction CD8+PD1+ PB. Intriguingly, early recurrent patients characterized carrying 1.5-fold lower PB, supporting double edge sword PD1 receptor. shares TIME, providing exploitable noninvasive tool intercept immunity cycle targetable pathways.