Chinese Society of Clinical Oncology breast cancer expert consensus on the diagnosis and treatment of breast cancer brain metastasis (2025)

Background: Globally, breast cancer (BC) ranks among the most frequently diagnosed malignant tumors in women. Given the high prevalence of BC, brain metastasis (BM) arising from this malignancy are the second most frequent type among patients surpassed only by those from lung cancer. This expert consensus aims to standardize the management of BC brain metastases (BCBM) and improve patient outcomes; it serves as a practical, evidence-based guide for clinicians and allied specialists. Methods: An expert panel comprising specialists from disciplines including medical oncology, breast surgery, neurosurgery, and pathology was convened. In developing this expert consensus, the expert panel conducted a comprehensive literature review and referenced authoritative guidelines from both domestic and international sources. Results: With advancements of systemic therapies, an expanding array of medications has demonstrated efficacy against BCBM, especially among individuals with human epidermal growth factor receptor 2 (HER2)-positive BCBM. In this consensus, we systematically evaluate the following key components: clinical manifestations, imaging assessments, pathological diagnosis, treatment strategies, prognostic outcomes, follow-up and post-treatment monitoring. Conclusions: This updated consensus incorporates significant revisions across key domains—including pathological diagnosis, chemotherapy, anti-HER2 targeted therapy, and the sequencing of radiotherapy and systemic treatments—while introducing new recommendations on imaging surveillance criteria and frequency, other targeted agents, and the integration of systemic therapy with local modalities.