Clinicopathological and molecular characteristics associated with PD-L1 expression in non-small cell lung cancer: a large-scale, multi-center, real-world study in China

Purpose The study aimed to evaluate the clinicopathological and molecular profiles associated with programmed death ligand 1 (PD-L1) expression in non-small cell lung cell (NSCLC) in a large-scale, multi-center, real-world Chinese cohort. Methods A total of 6295 NSCLC specimens from six centers in China were analyzed by PD-L1 (22C3) assay. PD-L1 expression in tumor cells (TCs) was classified as negative (TPS expression in < 1% of TCs), low (TPS in 1–49% of TCs), or high (TPS in ≥ 50% of TCs). The status of EGFR mutation was determined by reverse transcription polymerase chain reaction or next-generation sequencing, and ALK and ROS1 translocation was analyzed by immunohistochemistry and fluorescence in situ hybridization. Associations of PD-L1 expression with clinicopathological features and driver mutations were analyzed. Results Positive PD-L1 expression was more frequently seen in squamous cell carcinoma (SCC) and other histological types of NSCLC compared to adenocarcinoma (AC). In AC, PD-L1 expression was associated with gender, histological type, metastatic status, and pathological features of lymphovascular invasion and visceral pleural invasion. Solid and micropapillary subtypes of AC were more likely to have positive PD-L1 expression compared to other subtypes. PD-L1 was more highly expressed in biopsy samples than in resected samples, and in metastatic samples compared with primary tissues. PD-L1 expression was significantly associated with wild-type EGFR and ALK translocations. Conclusions PD-L1 expression in NSCLC is linked to histological type, pathological features, and driver mutation status, which has meaningful implications for clinical practice.