P2.09-16 Assessment of PD-L1 and CD8 Expression in Lung Cancer Using RNA in Situ Hybridisation

Abstract

p¼0.014). We found no significant correlation between PD-L1 or TIL infiltration with the number of mediastinal lymph nodes stations involved on pathological examination and with histological tumor subtypes (squamous cell carcinoma vs. adenocarcinoma). Conclusion: PD-L1 expression levels in TC and IC appeared similar in stage IIIA N2 NSCLC as compared to other stages. Expression in both TC and IC strongly correlated with TIL infiltration, suggesting a prominently immune-induced expression mechanism. Preoperative chemotherapy was associated with a higher TIL infiltration but not higher PD-L1 expression. Patients with skip N2 metastases harbored a higher level of TIL density, a finding consistent with a more active immune microenvironment in this group of patients with better prognosis. These data will be subsequently updated on a larger number of patient and correlated to clinical follow-up.