We chose Begg's funnel plot and Egger's test to detect the publication bias of our meta-analysis. A total of 23 studies evaluating the DFS/PFS of patients with multiple tumors yielded a Begg's and Egger's test scores of P = .460 and P = .379, respectively. At the same time, no publication biases were observed based on the funnel plot (Fig. 8B). However, the evaluation of the PD-L1 overexpression on the OS of patients in 60 studies yielded publication biases (Begg's test, P = .549 and Egger's test, P <.001) (Fig. 8A). Sensitivity analysis demonstrated that deleting any single study did not significantly affect the pooled HRs for OS and DFS/PFS (Supplementary Figs. 1 and 2, http://links.lww.com/MD/B655).
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