Background
Recent breakthroughs in therapies with immune checkpoint inhibitors (ICIs) have revolutionized the treatment of lung cancer. However, only 15-25% of patients respond to the ICIs therapy, and
Conclusions
Based on our results, our Simoa Epcam-PD-L1 EV detection assay is a potential liquid biopsy method to predict the PD-L1 expression level in patients with lung cancer.
Methods
In this study, we developed an Epcam-PD-L1 extracellular vesicle (EV) detection prototype using the Simoa platform. This assay detected PD-L1 expression levels on tumor-derived exosomes from the lung cancer cell lines A549 and SK-MES1. In addition, 35 plasma samples from patients with lung cancer were tested with this assay and the
Results
PD-L1 TPS-positive patients (≥1% IHC TPS) had significantly higher Simoa Epcam-PD-L1 signals than TPS-negative patients (<1% IHC TPS, P=0.026). The Simoa Epcam-PD-L1 area under curve (AUC) reached 0.776, with a sensitivity of 92.86% and a specificity of 71.43%. When PD-L1 TPS-positive patients were defined as having an IHC TPS ≥10%, the greatest difference in Epcam-PD-L1 signals was observed between IHC TPS-positive and IHC TPS-negative groups (P=0.0024) and the Simoa Epcam-PD-L1 AUC reached 0.832. Finally, the Spearman's correlation coefficient showed a significant correlation between the TPS and Simoa Epcam-PD-L1 signals (0.428, P=0.0104). Conclusions: Based on our results, our Simoa Epcam-PD-L1 EV detection assay is a potential liquid biopsy method to predict the PD-L1 expression level in patients with lung cancer.