Clin Lab. 2020 Dec 1;66(12). doi: 10.7754/Clin.Lab.2020.200325.
PD-L1 expression on tumor-infiltrating lymphocytes (TILs) has recently been reported as a biomarker for colorectal cancer (CRC). However, the prognostic and clinical significance of PD-L1 on TILs in CRC remains controversial. We performed this meta-analysis to evaluate the association between the PD-L1 expression on TILs and clinicopathological features and prognosis of CRC patients.
A comprehensive literature search for relevant studies published up to Feb 2020 was performed using Medline, Embase, and Web of Science. Odds ratio (OR) with 95% CI was selected to appraise the correlation between PD-L1 expression on TILs with prognostic and clinicopathological characteristics of CRC patients. Begg's and Egger's test were used to assess publication bias. The statistical analysis was conducted using Stata software.
A total of 19 studies including 5,213 CRC cases were included in this meta-analysis. The pooled results showed that PD-L1 overexpression on TILs was relevant to longer OS (OR = 1.36, 95% CI = 1.19 - 1.55, p < 0.01) and longer DFS/RFS (OR = 1.22, 95% CI = 1.03 - 1.44, p = 0.02). Moreover, CRC patients with high expression of PD-L1 on TILS was associated with lower T stage (OR = 2.30, 95% CI = 1.85 - 2.87, p < 0.01), less lymph node in-vasion (OR = 1.48, 95% CI = 1.03 - 2.13, p = 0.03), less distant metastasis (OR = 2.56, 95% CI = 1.81 - 3.64, p < 0.01), earlier TNM stage (OR = 1.93, 95% CI = 1.34 - 2.66, p < 0.01), later tumor grade (OR = 0.38, 95% CI = 0.23 - 0.62, p < 0.01) and high MSI status (OR = 0.36, 95% CI = 0.25 - 0.52, p < 0.01). But it is not related to tumor size, tumor differentiation, MMR status, BRAF mutant, and KRAS mutant.
This meta-analysis revealed that PD-L1 expression on TILs can serve as a significant biomarker for positive prognosis and clinicopathological features of CRC. Our results may provide some useful information when using PD-L1 expression to predict the survival of CRC patients and to select the beneficial CRC patients from PD-1/PD-L1 antibody treatment.
肿瘤浸润淋巴细胞（TILs）上的 PD-L1 表达最近被报道为结直肠癌（CRC）的生物标志物。然而，CRC 中 TILs 上 PD-L1 的预后和临床意义仍存在争议。我们进行了这项荟萃分析，以评估 TILs 上 PD-L1 表达与 CRC 患者的临床病理特征和预后之间的关系。
使用 Medline、Embase 和 Web of Science 对截至 2020 年 2 月发表的相关研究进行了全面的文献检索。选择比值比（OR）和 95%置信区间（CI）来评估 TILs 上 PD-L1 表达与 CRC 患者预后和临床病理特征之间的相关性。使用 Begg 和 Egger 检验评估发表偏倚。统计分析使用 Stata 软件进行。
这项荟萃分析共纳入了 19 项研究，包括 5213 例 CRC 病例。汇总结果表明，TILs 上 PD-L1 的过度表达与更长的总生存期（OR = 1.36，95%CI = 1.19 - 1.55，p < 0.01）和更长的无病生存期/无复发生存期（OR = 1.22，95%CI = 1.03 - 1.44，p = 0.02）相关。此外，TILS 上 PD-L1 高表达的 CRC 患者与较低的 T 分期（OR = 2.30，95%CI = 1.85 - 2.87，p < 0.01）、较少的淋巴结侵犯（OR = 1.48，95%CI = 1.03 - 2.13，p = 0.03）、较少的远处转移（OR = 2.56，95%CI = 1.81 - 3.64，p < 0.01）、较早的 TNM 分期（OR = 1.93，95%CI = 1.34 - 2.66，p < 0.01）、较低的肿瘤分级（OR = 0.38，95%CI = 0.23 - 0.62，p < 0.01）和较高的 MSI 状态（OR = 0.36，95%CI = 0.25 - 0.52，p < 0.01）相关。但与肿瘤大小、肿瘤分化、MMR 状态、BRAF 突变和 KRAS 突变无关。
这项荟萃分析表明，TILs 上 PD-L1 的表达可以作为 CRC 患者阳性预后和临床病理特征的重要生物标志物。我们的结果可能为使用 PD-L1 表达来预测 CRC 患者的生存并从 PD-1/PD-L1 抗体治疗中选择获益的 CRC 患者提供一些有用的信息。
