Study of Serum Soluble Programmed Death Ligand 1 as a Prognostic Factor in Hepatocellular Carcinoma in Egyptian Patients

Background: The expression of programmed cell death ligands on tumor cells has a role in the suppression of antitumor immunity, resulting in tumor immune evasion. Objective: In this study, we evaluated the prognostic value of the soluble form of programmed death-ligandl (sPD-L1) in Egyptian hepatocellular carcinoma (HCC) patients. Methods: This prospective cohort study was performed between November 2016 to November 2018 on 85 individuals (25 HCC patients, 25 HCC with vascular invasion and/or extrahepatic metastasis, 25 patients with liver cirrhosis, 10 healthy controls). The levels of sPD-L1 were determined in all subjects and compared in different groups and stages of cirrhosis and HCC. The association between sPD-L1 levels and overall survival (OS) was assessed. Results: Significant statistical difference in sPD-L1 was detected between different study groups. The cut-off value for normal sPD-L1 was defined by high sPD-L1 levels determined in a healthy control cohort. It was 2.522 ng/ml. In HCC patients, cut-off value was 7.42 ng/ml (sensitivity 88%, specificity 100%). In HCC with vascular invasion or metastasis, cut-off value was 9.62 ng/ml (sensitivity 88%, specificity 88%). Patients with high serum sPD-L1 or serum bilirubin concentrations had an increased risk of mortality. Conclusion: High sPD-L1 level could be a possible prognostic indicator for a poor outcome in liver cirrhosis and HCC patients. The predictive value of sPD-L1 levels for a successful anti- PD1/PD-L1 therapy should be investigated in the future.