Efficacy of PD-1 and PD-L1 inhibitors in triple-negative breast cancer: A meta-analysis of randomized controlled trials

Abstract

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer. PD-1 and PD-L1 inhibitors have recently shown promise when combined with chemotherapy to treat TNBC. This thesis aimed to evaluate the efficacy and safety of PD-1/PD-L1 inhibitors in TNBC through a meta-analysis of randomized controlled trials. Nine randomized controlled trials were included. This study covers both early-stage and advanced or metastatic TNBC. The main efficacy outcomes were pathological complete response (pCR) in early-stage TNBC and objective response rate (ORR) in advanced or metastatic TNBC. Safety was assessed using Grade ≥3 adverse events. The pooled analysis showed that PD-1/PD-L1 inhibitor plus chemotherapy significantly improved pCR in early-stage TNBC (OR = 1.82, 95% CI: 1.43-2.31; p < 0.00001) and ORR in advanced or metastatic TNBC (OR = 1.28, 95% CI: 1.09-1.51; p = 0.003). Safety analysis showed no statistically significant increase in Grade ≥3 adverse events with immunotherapy-based treatment compared with control therapy (RR = 1.04, 95% CI: 0.99-1.11; p = 0.14). Overall, the findings suggest that PD-1/PD-L1 inhibitors combined with chemotherapy provide meaningful clinical benefit in TNBC.