Published in:
Open Access 01-12-2019 | Hepatocellular Carcinoma | Primary research
Prognostic role of PD-L1 for HCC patients after potentially curative resection: a meta-analysis
Published in: Cancer Cell International | Issue 1/2019
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Background
A series of studies has investigated the prognostic role and clinical significance of programmed death ligand 1 (PD-L1) in hepatocellular carcinoma (HCC). However, the results were inconsistent. We aimed to clarify the prognostic role of PD-L1 and relationship between PD-L1 expression and several important clinicopathological features.
Methods
PubMed, EMBASE and the Science Citation Index Expanded were systematically searched. All cohort or case–control studies comparing the prognosis and clinical features between the high PD-L1 and low PD-L1 groups were included. Publication bias was evaluated using funnel plots and Begg’s test. Subgroup analysis, sensitivity analysis and meta-regression analysis were performed.
Results
Seventeen studies including 2979 patients were eligible. The overall survival (OS) was not significantly different between the high and low PD-L1 groups (hazard ratio [HR]: 1.27; 95% confidence interval [CI] 0.98–1.65: P = 0.07) with significant heterogeneity (P < 0.001; I2 = 81%). The recurrence-free survival (RFS) was not significantly different between the high and low PD-L1 groups (HR: 1.22; 95% CI 0.97–1.53; P = 0.09) with significant heterogeneity (P < 0.001; I2 = 78%). The expression of PD-L1 was found to be significantly correlated with alpha-fetoprotein, hepatitis history, and tumour-infiltrating lymphocytes. Begg’s test found no significant publication bias for OS and RFS. Sensitivity analysis established the robustness of our results. Subgroup analysis and meta-regression analysis found the region of research as a significant contributor to inter-study heterogeneity in RFS, indicating some racial differences in the prognostic role of PD-L1.
Conclusions
Our study found no significant prognostic role of PD-L1 in HCC patients after potential curative hepatectomy based on our included studies. The expression of PD-L1 was significantly correlated with AFP, hepatitis history, and TILs. The prognostic role of PD-L1 in HCC warrants further investigation.