Clinicopathological And Molecular Parameters Of Lung Adenocarcinomas (Adc) Associated With Programmed Cell Death Ligand 1 (Pd-L1) Protein Expression.

7555 Background: Recent efforts in targeting the PD-1/PD-L1 pathway in solid tumors have resulted in durable responses in early phase clinical trials. Additionally, it has been reported that PD-L1 overexpression by immunohistochemistry (IHC) could serve as a predictor of patient response to anti-PD-1/PD-L1 therapies. However, the association of clinicopathological and molecular features with PD-L1 expression in ADC is not well-defined. Methods: PD-L1 (E1L3N, Cell Signaling Technology) and CD8 IHC were performed on tissue microarrays of 242 resected ADC that underwent detailed histological analysis. Clinical molecular testing had been performed in a subset (n = 128). Membranous expression of PD-L1 (any intensity) in 5% or more tumor cells was defined as positive. CD8+ tumor infiltrating lymphocytes (TILs) were evaluated using a 4-tier grading system (0-3). PD-L1 expression was correlated with clinicopathological and molecular features as well as prognosis. Results: Pathologic stage was 0 in 1, I in 188, II...