Liu Gao-Min, Li Xu-Gang, Zhang Yao-Min
The 2nd Department of Hepatobiliary Surgery, Meizhou People's Hospital, No. 34 Huangtang Road, Guangdong, 514031 China.
Cancer Cell Int. 2019 Jan 29;19:22. doi: 10.1186/s12935-019-0738-9. eCollection 2019.
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.
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.
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; I = 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; I = 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.
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.
一系列研究探讨了程序性死亡配体1（PD-L1）在肝细胞癌（HCC）中的预后作用和临床意义。然而，结果并不一致。我们旨在阐明PD-L1的预后作用以及PD-L1表达与几个重要临床病理特征之间的关系。
系统检索了PubMed、EMBASE和科学引文索引扩展版。纳入所有比较高PD-L1组和低PD-L1组预后及临床特征的队列研究或病例对照研究。使用漏斗图和Begg检验评估发表偏倚。进行亚组分析、敏感性分析和meta回归分析。
17项研究共2979例患者符合纳入标准。高PD-L1组和低PD-L1组的总生存期（OS）无显著差异（风险比[HR]：1.27；95%置信区间[CI]0.98-1.65：P = 0.07），存在显著异质性（P < 0.001；I = 81%）。高PD-L1组和低PD-L1组的无复发生存期（RFS）无显著差异（HR：1.22；95%CI 0.97-1.53；P = 0.09），存在显著异质性（P < 0.001；I = 78%）。发现PD-L1的表达与甲胎蛋白、肝炎病史和肿瘤浸润淋巴细胞显著相关。Begg检验发现OS和RFS无显著发表偏倚。敏感性分析证实了我们结果的稳健性。亚组分析和meta回归分析发现研究地区是RFS研究间异质性的一个重要因素，表明PD-L1的预后作用存在一些种族差异。
基于我们纳入的研究，我们的研究发现PD-L1在潜在根治性肝切除术后的HCC患者中无显著预后作用。PD-L1的表达与甲胎蛋白、肝炎病史和肿瘤浸润淋巴细胞显著相关。PD-L1在HCC中的预后作用值得进一步研究。
