PUB115 Clinical Significance of PD-L1 Status and the Expression of PD-1 in Tumor-Infiltrating Lymphocytes (TILs) in Lung Cancer

Abstract

PD-L1 status in lung cancer may be a predictive biomarker for the use of PD1/PD-L1 inhibitors. Nonetheless, it is still unclear which immunohistochemistry platform for PD-L1 assessment should be implemented for optimal prognostic/predictive information. We investigated whether the PD-L1 status in early-stage lung cancer is associated with specific clinical features or survival, as well as the PD1 expression in TILs. IHC was performed on FFPE surgical tumors, arrayed on tissue microarrays with duplicate cores. PD-L1 status was assessed with two ABs: Ventana (SP124) (PD-L1V) and Cell Signaling (E1L3N) (PD-L1CS). PD1 expression in TILs was determined with the AB Ventana (NAT105). All patients (n=482) had early stage T1/T2-N0 and underwent curative surgery between 1987 and 2002. PD-L1 membranous staining was scored as positive if >5% of tumor cells. PD1 was considered as positive if >10% in TILs. Tabled 1PD-L1(V)PD-L1(CS)PD1All cases (including carcinoids)7%18%50%Histology Sq Non-Sqp=0.0043 12% 4%p<0.0001 30% 12%56% 49%pStage IA IB5% 10%p=0.017 15% 24%51% 53%Grading G1 G2 G3p=0.004 1% 6% 12%p=0.0002 7% 18% 27%p=0.001 41% 45% 61% Open table in a new tab Patient’s median age (IQR) 68 years (59-73), gender male/female 53%/47%, smoking status never/former/current/missing 14%/26%/49%/11%, histology squamous-cell carcinoma (Sq)/Non-squamous (Non-Sq)-NSCLC/carcinoid 37%/55%/7%, p-stage IA/IB 52%/48%. A table shows the association between biomarker status (PD-L1(V), PD-L1(CS) and PD1 )and tumor features (including Pearson’s Chi-Square p-values <0.05). All carcinoids were negative for PD-L1, except for one. The degree of agreement between the two PD-L1 Abs was moderate (Kappa=0.47). Median OS was 76 months. No statistically significant association between PD-L1 status and OS was observed. PD1 expression in TILs was associated with worse survival in Sq tumors. Median OS for cases with PD1 positive vs negative TILs was 54 vs 79 months, respectively (log-rank p=0.08; Wilcoxon p=0.02). In this study we observed a higher expression of PD-L1 using the CS antibody with a moderate agreement between the two antibodies. Sq tumors showed a significantly higher expression of PD-L1 compared with non-Sq tumors. PD-1 expression in TILs was associated with worse survival in Sq tumors.