Clinicopathological and prognostic significance of PD-L1 expression in colorectal cancer: a meta-analysis

Abstract

Purpose To systematically evaluate the correlation between PD-L1 expression and clinicopathological features and prognosis of colorectal cancer (CRC). Methods Seven databases (PubMed, Cochrane Library, EMBASE, Web of Science, CBM, Wanfang, and CNKI) were searched through May 2020. Risk of bias and quality of evidence were assessed by using the Newcastle–Ottawa scale (NOS), and meta-analysis was carried out by using the Review Manager 5.3 software on the studies with the quality evaluation scores ≥ 6. Meta-regression analysis was used to determine the independent role of PD-L1 expression on CRC prognosis after adjusting clinicopathological features and treatment methods. Results A total of 8823 CRC patients in 32 eligible studies. PD-L1 expression was correlated with lymphatic metastasis (yes/no; OR = 1.24, 95% CI (1.11, 1.38)), diameter of tumor (≥ 5 cm/< 5 cm; OR = 1.34, 95% CI (1.06, 1.70)), differentiation (high–middle/low; OR = 0.68, 95% CI (0.53, 0.87)), and vascular invasion (yes/no; OR = 0.80, 95% CI (0.69, 0.92)). PD-L1 expression shortened the overall survival (hazard ratio (HR) = 1.93, 95% CI (1.66, 2.25)), disease-free survival (HR = 1.76, 95% CI (1.50, 2.07)), and progression-free survival (HR = 1.93, 95% CI (1.55, 2.41)). Meta-regression showed that PD-L1 expression played a significant role on poor CRC OS (HR = 1.95, 95% CI (1.92, 3.98)) and disease-free survival (HR = 2.14, 95% CI (0.73, 4.52)). Conclusion PD-L1 expression independently predicted a poor prognosis of CRC.

Programmed death ligand‐1 regulates angiogenesis and metastasis by participating in the c‐JUN/VEGFR2 signaling axis in ovarian cancer

“…By performing IHC staining assay with primary and metastatic ovarian cancer tissues and survival analysis, we further proved that PD‐L1 could be regarded as a prognostic risk factor and induce ovarian cancer progression and metastasis. Previous studies have reported similar results in other types of cancer, such as head and neck cancer [41], colorectal cancer [42], endometrial cancer [43], and clear cell renal cell carcinoma [44]. PD‐L1 was also found to play a vital role as a poor prognosis predictor in patients with biliary tract cancer [45].…”

Development and Validation of a TNF Family-Based Signature for Predicting Prognosis, Tumor Immune Characteristics, and Immunotherapy Response in Colorectal Cancer Patients

“…However, the recurrence rate of CRC within 2 years after undergoing radical resection has been reported to be high (nearly 50%), and half of the relapses were fatal [2]. Immunotherapy, especially inhibitors targeting immune checkpoints, including cytotoxic T-lymphocyte antigen-4 (CTLA4), programmed cell death protein 1 (PD-1), and programmed cell death 1 ligand 1 (PD-L1), has provided promising new approaches to improve the overall survival (OS) of patients with CRC [3][4][5][6]. In particular, recent studies have demonstrated that pembrolizumab (an anti-PD-1 monoclonal antibody) had improved efficacy and long-term clinical benefit for the subgroup of patients with microsatellite instability-high (MSI-H)/DNA mismatch repair-deficient (dMMR) CRC [7,8].…”

PD-L1 Expression Is Associated with Deficient Mismatch Repair and Poor Prognosis in Middle Eastern Colorectal Cancers

“…Interestingly, multivariate analysis showed that PD-L1 expression was a predictive marker for OS in the entire cohort. Analogously, a recent large metaanalysis by Wang et al [39] in a large cohort of 8823 CRC patients from 32 studies also showed that PD-L1 expression was an independent predictor for poor OS. Another metaanalysis comprising 13 studies with 3905 CRC patients also showed a significant association between expression of PD-L1 and poor OS [40].…”