Comparative Study of PD-L1 Expression in Different Sites of 
Non-small Cell Lung Cancer

This study aims to explore the differences of PD-L1 expression in test samples obtaining from different sites of NSCLC. This study may contribute to the detection strategy of PD-L1 in patients with advanced lung cancer. Methods One hundred and thirty-one cases of consecutively detected PD-L1 (22c3 assay, Dako) staining in metastatic NSCLC and 972 cases of non-paired intrapulmonary NSCLC were collected. The discrepancies of tumor proportion score (TPS) of PD-L1 expression in intrapulmonary samples and extrapulmonary metastatic samples of different sites were compared. Results The positive expression rate of PD-L1 in extrapulmonary metastatic NSCLC (TPS ≥ 1%) was 61.83%, and the TPS was significantly higher than that in intrapulmonary tumors (P=0.03). The PD-L1 scores of the specimens obtained from different sites were significantly different (P=0.007). The positive rates of PD-L1 in liver and adrenal metastases were 85.71% and 77.78% respectivel y, and their TPS were significantly higher than that of the intrapulmonary samples (P
Source: Chinese Journal of Lung Cancer - Category: Cancer & Oncology Source Type: research