Abstract:Objective To evaluate the safety of pembrolizumab in the treatment of early triple-negative breast cancer (ETNBC) by meta-analysis.Methods Computer searches were conducted on PubMed, Web of Science, Cochrane databases, Embase, ClinicalTrials.gov, CNKI, Wanfang, and CBM to collect clinical trials of traditional chemotherapy combined with pembrolizumab (experimental group) compared to traditional chemotherapy combined with placebo (control group) or paclitaxel combined with pembrolizumab (experimental group) compared to paclitaxel combined with placebo (control group). The search period was from database establishment to April 1, 2023. After screening literature, extracting data, and evaluating quality, RevMan 5.3 software was used for statistical analysis and sensitivity analysis.Results A total of 1 509 patients were included in 3 articles. The outcome indicators, which were grade 3~5 adverse events in the trials, mainly inlcuded diarrhea, neutropenia, anemia, fatigue, and skin reactions. The meta-analysis results showed that there was no statistically significant difference in the incidence of grade 3~5 adverse events between the experimental group and the control group, including diarrhea (RR=1.83, 95% CI: 0.81~4.12, P=0.15), neutropenia (RR=1.03, 95% CI: 0.88~1.20, P=0.73), anemia (RR=1.20, 95% CI: 0.92~1.55, P=0.18), and skin reactions (RR=3.14, 95% CI: 0.28~35.41, P=0.35). In terms of fatigue incidence, there was a statistically significant difference between the experimental group and the control group (RR=2.21, 95% CI: 1.03~4.76, P=0.04). The incidence rate of fatigue was 3.4% in the experimental group , but it was 1.3% the control group.Conclusion In terms of common adverse events, the use of pembrolizumab may increase the probability of fatigue in patients, but in terms of overall incidence of adverse events and other common adverse events, it does not increase the risk of adverse events in patients. It has acceptable safety and is well tolerated in ETNBC patients.