A Meta-Analysis of Efficacy and Safety of PD-1/PD-L1 Inhibitors in Triple-Negative Breast Cancer

Objective. To evaluate the efficacy and safety of programmed cell death receptor-1 (PD-1)/programmed cell death-ligand protein-1 (PD-L1) inhibitors in triple-negative breast cancer (TNBC) to provide a treatment basis for TNBC. Methods. Published case-control studies on PD-1/PD-L1 inhibitors in the treatment of TNBC were retrieved from PubMed, Embase, and Cochrane Library databases, and collected data were processed by RevMan 5.4. Results. A total of 7 studies with 4340 study subjects were obtained, including 2092 PD-L1-negative cases, 1375 PD-L1-positive cases, and 847 PD-L1 unidentified cases. The use of PD-1/PD-L1 inhibitors showed no significant impact on patients’ progression-free survival (PFS) and overall survival (OS). The use of PD-1/PD-L1 inhibitors in the PD-L1-positive subgroup significantly improved patients’ PFS and OS. Treatment with PD-1/PD-L1 inhibitors presented no significant effect on the incidence of adverse events (AEs) but increased the risk of AE grade ≥3 and severe AEs (SAEs). Conclusion. PD-1/PD-L1 inhibitors are effective in the treatment of TNBC, which is strongly correlated with the expression of PD-L1; patient selection and clinical application require further investigation and verification.