Evaluating the Efficacy and Safety of PD-L1 Monoclonal Antibody Combined With VEX Metronomic Chemotherapy and Concurrent or Delayed Radiotherapy in Patients With Advanced HER2-Negative Breast Cancer With Brain Metastasis
A Prospective, multicenter, randomized controlled phase II study to evaluate the efficacy and safety of PD-L1 monoclonal antibody combined with vinorelbine + cyclophosphamide + capecitabine (VEX) metronomic chemotherapy and concurrent or delayed radiotherapy in patients with advanced HER2-negative breast cancer with brain metastasis