Evaluate soluble PD-L1 in plasma in advanced stage non-small cell lung cancer patients

Abstract

Background: Programmed cell death receptor 1 (PD-1) and its ligand (PD-L1 - programmed cell death – 1 ligand) play an important role in immune response and immunotherapy for lung cancer patients. Soluble PD-L1 (sPD-L1) can be determined in the peripheral blood of cancer patients. Many studies have desmonstrated that high membrane-bound PD-L1 (mPD-L1) expression in tumor tissue associated with poor prognosis in cancer patients. This study evaluated circulating PD-L1 concentration and the association between sPD-L1 and mPD-L1 and other clinical characteristics in patients with advanced stage non-small cell lung cancer (NSCLC). Methods: This study was conducted on 50 inpatients diagnosed NSCLC with evidence of histopathology and immunohistochemistry, treated in Respiratory Center, Military Hospital 103 from January to September 2019. It was cross-sectional descriptive study with analysis. Soluble PD-L1 was measured on peripheral blood samples by ELISA assay. mPD-L1 expression on lung cancer tissue was performed by immunohistochemistry technique using 73-10 PD-L1 antibody. Results: The average sPD-L1 concentration was 2.11 ± 1.48 ng/mL (Range: 0.24 - 5.56 ng/mL). There was no statistically significant difference between sPD-L1 concentration with gender, tumor size, TNM stage of disease, histopathological types and mPD-L1 expression. sPD-L1 concentration was significantly lower in patients with smoking (1.12 ± 0.69 ng/mL) compared with the non-smoking group (2.22 ± 1.51 ng/mL) (p = 0.018). Conclusions: The mean PD-L1 of the peripheral blood serum in advanced stage NSCLC patients was 2.11 ± 1.48 ng/mL. sPD-L1 was significantly lower in smoking patients compared with non-smoking group.