Expression and Prognostic Value of Tumor-Infiltrating Lymphocytes and PD-L1 in Hepatocellular Carcinoma

AIM: To explore the difference in tumor-infiltrating lymphocytes (TILs) and programmed death-ligand (PD-L1) in primary hepatocellular carcinoma (HCC) and its adjacent tissues, and to evaluate their effect on HCC prognosis. METHODS: Liver cancer and paracancerous tissue samples were collected from 72 patients who underwent radical hepatectomy between December 15, 2017 and January 9, 2019. Flow cytometry was used to detect the distribution of TILs and PD-L1, analyze the correlation between the expression of CD8/CD3 and PD-L1 and clinical-pathological parameters, and evaluate their effect on the prognosis of HCC patients. RESULTS: The distribution proportion of CD3+T cells, CD4+T cells, and PD-L1 in liver cancer were significantly higher than in paracancerous tissues, while the distribution proportion of CD8+T cells was significantly lower (all P<0.05). In HCC, the distribution proportion of CD8+T cells was related to tumor size and stage, while the PD-L1 expression was related to the tumor stage only (all P < 0.05). Univariate analysis showed that tumor differentiation, TNM stage, expression of CD8/CD3, and PD-L1 in tumor tissue were related to disease-free survival (DFS)(P < 0.05); multivariate Cox regression analysis showed that tumor differentiation, TNM stage, CD8/CD3, and PD-L1 expression were independent influencing factors of postoperative DFS (P < 0.05). Kaplan–Meier survival curve analysis showed that the DFS of CD8/CD3 high expression group was significantly higher than that of the low expression group, and the DFS of PD-L1 low expression group was significantly higher than that of the high expression group (all P < 0.05). CONCLUSION: There are significant differences in the distribution of TILs and PD-L1 in HCC and paracancerous tissues. The expression of CD8/CD3 and PD-L1 in tumor-infiltrating lymphocytes in HCC may help evaluate the immunological indexes of prognosis after radical resection of HCC and to further the study of immunotherapy in patients with HCC.