虽然程序性细胞死亡配体1（PD-L1）在血液恶性肿瘤中的表达和功能引起了广泛关注，但其在非淋巴结自然杀伤/ T细胞淋巴瘤（ENKTL）的预后价值尚不清楚。因此，我们进行了这项荟萃分析，以探讨肿瘤PD-L1表达对ENKTL的预测价值。在PubMed、Embase、Web of Science和CNKI数据库中搜索符合条件的观察性研究，报告ENKTL患者的PD-L1表达和生存结局。搜索遵循流行病学观察研究的荟萃分析（MOOSE）指南。采用合并风险比（HR）和95%置信区间（95% CI）分析生存结局，并采用比值比（OR）和95% CI分析临床病理参数。统计分析使用Review Manager 5.3和STATA 17.0软件。通过漏斗图和Egger's检验评估潜在的出版偏倚。 共包括7项研究，纳入了433名ENKTL患者。合并结果显示肿瘤PD-L1表达与总生存率（OS）之间没有显著关系（HR=1.35，95% CI：0.49-3.75，P=0.559）。我们还进行了亚组分析。然而，增加的PD-L1表达与低国际预后指数（IPI）评分的0-1（OR = 2.46；95% CI：1.11-5.45，P=0.03）、良好的治疗状况（OR = 1.97；95% CI：1.11-3.51，P=0.02）以及良好的治疗效果（OR = 2.61；95% CI：1.01-6.70，P=0.05）相关。ENKTL患者中的PD-L1阳性表达与有利的临床特征相关。因此，PD-L1阳性表达似乎是治疗受益的潜在预测因子。需要进一步开展大规模、高质量的研究来进一步探讨其预测价值。2023 Translational Cancer Research保留所有权利。

Although programmed cell death ligand 1 (PD-L1) expression and function in hematologic malignancies have aroused extensive attention, its prognostic value for extranodal natural killer/T-cell lymphoma (ENKTL) is still unknown. Therefore, we conducted this meta-analysis to explore the predictive value of neoplastic PD-L1 expression for ENKTL.The PubMed, Embase, Web of Science, and CNKI databases were searched to identify eligible observational studies reporting PD-L1 expression and survival outcomes of ENKTL patients. The search was conducted in accordance with the Meta-analyses Of Observative Studies in Epidemiology (MOOSE) guidelines. The pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were adopted to analyze survival outcomes, and the odds ratios (ORs) and 95% CIs were adopted for clinicopathological parameters. Review Manager 5.3 and STATA 17.0 were used for statistical analysis. Potential publication bias was evaluated by funnel plot and Egger's test.A total of 433 patients with ENKTL were included across seven studies. The pooled results showed no significant relationship between neoplastic PD-L1 expression and overall survival (OS) (HR =1.35, 95% CI: 0.49-3.75, P=0.559). We also performed subgroup analyses. However, increased PD-L1 expression was associated with a low international prognostic index (IPI) score of 0-1 (OR =2.46; 95% CI: 1.11-5.45, P=0.03), good performance status (OR =1.97; 95% CI: 1.11-3.51, P=0.02), and a good treatment effect (OR =2.61; 95% CI: 1.01-6.70, P=0.05).PD-L1-positive expression in patients with ENKTL was correlated with favorable clinical features. Thus, PD-L1-positive expression appears to be a potential predictor of treatment benefits. Additional large-scale, high-quality studies are needed to further explore its predictive value.2023 Translational Cancer Research. All rights reserved.