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
Males or females who are at least 18 years of age on the day of signing the informed consent form.
Patients with metastatic HER2-negative breast cancer brain metastasis, with clear clinical documentation; specific criteria refer to the guidelines of the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP).
Patients who have received no more than one line of chemotherapy during the metastatic stage of breast cancer.
The patient has not previously received intracranial radiotherapy.
The subject has leptomeningeal metastasis.
If the patient has concurrent brain metastasis, the neurological symptoms are too severe to cooperate with radiotherapy.
Malabsorption syndrome, or the disease significantly affects gastrointestinal function; or after subtotal gastrectomy, or after proximal small bowel resection, which may affect the absorption of oral metronomic chemotherapy agents.
The subject has dysphagia or is unable to swallow tablets.