Correlation of PD-L1 and SOCS3 Co-expression with the Prognosis of Hepatocellular Carcinoma Patients

Purpose: To investigate the correlation between the expression of PD-L1, SOCS3 and immune-related biomarkers CD276, CD4, CD8 in hepatocellular carcinoma (HCC) and further determine the relationship with clinicopathologic characteristics and the prognostic value of their co-expression in HCC patients. Methods: We assessed the expression of PD-L1, CD276, SOCS3, CD4 and CD8 by immunohistochemistry in tumor tissue from 74 HCC patients who underwent curative hepatectomy. Results: High expression of PD-L1 was significantly associated with high Edmondson grade (p<0.01) and elevated enzyme (p=0.037); high expression of CD276 was significantly correlated with high Edmondson grade (p=0.021); high expression of SOCS3 was significantly associated with age (p=0.026) and tumor size (p=0.041), while PD-L1 showed no significant correlation. The expression of PD-L1, CD276, SOCS3 protein and other clinicopathological factors (sex, vascular invasion, tumor number, tumor capsule, pT stage, liver cirrhosis, HBsAg, TBiL, AFP) showed no significant correlation (p>0.05). High expression of CD8 was respectively significantly associated with worse overall survival (OS) (p=0.002). There was no significantly difference between CD4 and CD8 high-expression and overall survival (OS) (p=0.100). Both high expression of PD-L1 (p=0.003) and low expression of SOCS3 (p=0.015) was significantly associated with worse overall survival (OS). But CD276 only had a trendency (p=0.166). Additionally, multivariate Cox regression models implied that PD-L1, SOCS3, as well as both CD4 and CD8 was an independent prognostic factor for OS (p<0.05). Furthermore, HCC patients with PD-L1 low-expression and SOCS3 high-expression had a better prognostic according to the different pT stages (p<0.05). Conclusions: We for the first time demonstrated that PD-L1 and SOCS3 were independent prognostic factor for HCC patients. Co-expression of low PD-L1 and high SOCS3 could be a better predictive marker for HCC patients.