P34.02 Detection of PD-L1 Expression and Its Clinical Significance in Circulating Tumor Cells From Patients With Non-Small-Cell Lung Cancer

The expression of programmed cell death ligand 1(PD-L1) is related to the efficacy of immune checkpoint inhibitors on patients with non-small cell lung cancer (NSCLC), but its clinical tissue samples are difficult to obtain, and initial tumor tissue (TT) samples are difficult to reflect the spatial-temporal heterogeneity of the tumor due to treatment and disease progression. Liquid biopsy plays a crucial role in individualized and precise treatment of tumors. Therefore, we explored the feasibility of separating circulating tumor cells (CTCs) based on size and detecting PD-L1 expression on CTCs, with the goal of laying a foundation for real-time individualized immunotherapy.