SBRT Combined With PD-1 Inhibitor and Chemotherapy in Early-stage TNBC

Triple-negative breast cancer (TNBC) presents significant challenges due to its limited treatment options and poor efficacy. While neoadjuvant chemotherapy has improved breast-conserving rates and extended survival for TNBC patients, this subtype still faces issues such as restricted treatment modalities, low pathological response rates, and unfavorable prognosis compared to other subtypes. Studies like Keynote522 and IMpassion031 have shown that combining chemotherapy with immunotherapy yields a pCR rate of 64.8% in early-stage high-risk TNBC patients, suggesting that such combinations can offer substantial benefits. However, the low immunogenicity of breast cancer and the lack of clear predictive molecular markers for effective immunotherapy result in suboptimal pCR and objective response rates for this group. Radiotherapy has systemic immune regulatory effects by promoting the release of antigens from tumor cells, enhancing T-cell infiltration, and directly killing tumor cells. Therefore, this study aims to investigate the efficacy and safety of stereotactic radiotherapy combined with PD-1 inhibitors and chemotherapy in the neoadjuvant treatment of TNBC.