Supplementary Material for: Association between PD-L1 Expression and the Prognosis and Clinicopathologic Features of Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

The expression of programmed cell death-ligand 1 (PD-L1) and its correlation with the prognosis and clinicopathologic features of renal cell carcinoma (RCC) remain controversial to date. Concerning this issue, we had conducted a meta-analysis of relevant studies searched in the Web of Science, PubMed, EMBASE, and Cochrane Library databases. The Newcastle-Ottawa quality assessment scale was applied to assess the quality of the included studies. The hazard ratio (HR) and its corresponding 95% confidence intervals (CIs) were collected by Stata 12.0 and used for the results of overall survival (OS) and disease-free survival (DFS). A total of 1,644 patients in 8 studies were included in this meta-analysis. Results showed that PD-L1 expression significantly correlated with OS (HR = 1.98, 95% CI: 1.22–3.22, <i>Z</i> = 2.77, <i>p</i> = 0.006) and DFS (HR = 3.70, 95% CI: 2.07–6.62, <i>Z</i> = 4.40, <i>p</i> = 0.0001) in ccRCC. Subgroup analysis indicated that PD-L1 expression significantly correlated with the lymph-gland transfer ratio (HR = 2.45, 95% CI: 1.02–5.92, <i>Z</i> = 1.99, <i>p</i> = 0.05) and tumor necrosis (HR = 6.05, 95% CI: 3.78–9.67, <i>Z</i> = 7.51, <i>p</i> &lt; 0.00001). This meta-analysis suggests that PD-L1 expression is a valuable prognostic tool for patients with ccRCC. Subgroup analyses demonstrated that it was helpful for screening patients with RCC who need anti-PD-1/PD-L1 treatment and support them to benefit from such immune-targeted therapy.

截至目前，程序性死亡配体1（programmed cell death-ligand 1，PD-L1）的表达水平及其与肾细胞癌（renal cell carcinoma，RCC）预后和临床病理特征的相关性仍存在争议。针对这一争议问题，本研究对检索自Web of Science、PubMed、EMBASE及Cochrane Library数据库的相关研究开展了一项荟萃分析。采用纽卡斯尔-渥太华质量评估量表（Newcastle-Ottawa quality assessment scale）对纳入研究的方法学质量进行评价。采用Stata 12.0软件提取风险比（hazard ratio，HR）及其对应的95%置信区间（95% confidence intervals，CIs），用于总生存期（overall survival，OS）与无病生存期（disease-free survival，DFS）的结果分析。本项荟萃分析共纳入8项研究，涉及1644例患者。结果显示，在透明细胞肾细胞癌（clear cell renal cell carcinoma，ccRCC）中，PD-L1表达与总生存期（HR=1.98，95%CI：1.22~3.22，Z=2.77，*P*=0.006）及无病生存期（HR=3.70，95%CI：2.07~6.62，Z=4.40，*P*=0.0001）均存在显著相关性。亚组分析结果显示，PD-L1表达与淋巴结转移比（HR=2.45，95%CI：1.02~5.92，Z=1.99，*P*=0.05）及肿瘤坏死（HR=6.05，95%CI：3.78~9.67，Z=7.51，*P*<0.00001）均存在显著相关性。本项荟萃分析表明，PD-L1表达可作为透明细胞肾细胞癌患者极具价值的预后评估工具。亚组分析进一步证实，PD-L1表达可用于筛选需接受抗PD-1/PD-L1治疗的肾细胞癌患者，并助力其从此类免疫靶向治疗中获益。