Immunotherapy Targeting PD-1/PD-L1 in Early-Stage Triple-Negative Breast Cancer

The advent of immunotherapy, especially immune checkpoint inhibitors (ICIs), has revolutionized antitumor therapy. Programmed cell death receptor 1 (PD-1) and programmed cell death ligand 1 (PD-L1) are among the most promising targets for encouraging the immune system to eliminate cancer cells. PD-1/PD-L1 have made clinical remission for numerous solid tumors, including metastatic triple-negative breast cancer (TNBC). In recent years, integrating PD-1/PD-L1 inhibitors into existing treatments in early-stage TNBC has attracted wide attention. Herein, we summarize the clinical benefit of PD-1/PD-L1 inhibitors plus neoadjuvant chemotherapy, adjuvant chemotherapy, and targeted therapy in early-stage TNBC. Possible immunotherapy biomarkers, immune-related adverse events (irAEs), and the key challenges faced in TNBC anti-PD-1/PD-L1 therapy are also concluded. Numerous studies on immunotherapy are ongoing, and PD-1/PD-L1 inhibitors have demonstrated great clinical prospects in early-stage TNBC. To maximize the efficacy of anti-PD-1/PD-L1 therapy, further research into the challenges which still exist is necessary.