[Perioperative Breast Cancer Treatment with Immune Checkpoint Inhibitors-Current Status and Future Perspectives]

Immune checkpoint inhibitors (ICIs) represent a breakthrough in cancer immunotherapy and have become standard treatment for several solid tumors. Although breast cancer has traditionally been considered a tumor with low immunogenicity, the clinical utility of ICIs has been demonstrated, particularly in triple-negative breast cancer (TNBC). In the perioperative setting for TNBC, the KEYNOTE-522 trial showed that the addition of pembrolizumab to chemotherapy significantly improved pathological complete response (pCR) rates, event-free survival (EFS), and overall survival (OS), establishing a new standard of care. For hormone receptor-positive (HR+)/HER2-negative breast cancer, the KEYNOTE-756 and CheckMate 7FL trials have suggested the potential efficacy of perioperative ICIs, with particularly promising results in patient subgroups with low estrogen receptor (ER) expression and PD-L1 positivity. However, several challenges remain, including the establishment of predictive biomarkers, management of immune-related adverse events, and overcoming resistance mechanisms. Future directions include the optimization of biomarker-guided patient selection, the development of novel combination therapies with antibody-drug conjugates (ADCs) and PARP inhibitors, and the clinical development of next-generation immunotherapies such as CAR-T cell therapy and tumor-infiltrating lymphocyte (TIL) therapy, with the goal of extending the benefits of immunotherapy to a broader population of breast cancer patients.