Risk Analysis of Positive PD-L1 Expression and Clinicopathological Features and Survival Prognosis in Patients with Colorectal Cancer: Systematic Review and Meta-Analysis.

In order to explore the significance of PD-L1 expression in the prognosis and clinicopathological characteristics of colorectal cancer (CRC), the PubMed, Embase, Web of Science, Cochrane Library, CNKI, and multisquare databases are systematically searched for the relevant relationship between PD-L1 expression and CRC prognosis. The search time is completed until June 2021. Literature is filtered and data extracted by inclusion exclusion criteria, and Meta-analysis is performed with Stata SE12.0 software. 16 documents are included, and a total of 1997 CRC patients are included. The results show that recurrence-free survival (RFS) [OR = 2.69, 95%CI (2.07,3.48),  < 0.00001, I = 0%,  = 7.50), and disease-free survival (DFS) (OR = 3.71, 95% CI (2.32,5.93),  < 0.00001, I = 37%,  = 5.48) and PD-L1 expression and tumor differentiation (OR = 4.00, 95%CI (2.97,5.38),  < 0.00001, I = 0%,  = 9.11) and lymphatic action metastasis (OR = 2.69,95% CI (2.07,3.48),  < 0.00001, I = 0%,  = 7.50) is significantly associated.PD-L1 expression in tumor tissue suggests a poor prognosis in colorectal cancer, and the predictive significance of PD-L1 expression and PD-L1 expression in tumor cells in tumor-infiltrating immune cells may be inconsistent.