A team of researchers led by Dr. Suling Liu from The First Affiliated Hospital of Zhejiang University has published a comprehensive review on breast cancer brain metastasis (BCBrM), a devastating complication with limited treatment options and poor prognosis.

The article, co-authored by Jing Feng, Yuwei Tao, and Fengkai Li, systematically analyses the biological mechanisms, preclinical models, and therapeutic innovations in BCBrM.

BCBrM occurs in approximately 5–20% of breast cancer patients and is especially common in HER2-positive and triple-negative subtypes.

As systemic therapies improve survival, the incidence of BCBrM is rising, underscoring the urgent need for effective brain-targeted treatments.

The review outlines the metastatic cascade, beginning with local invasion and intravasation, followed by circulation, BBB extravasation, and colonisation in the brain.

Key molecular pathways, such as TGF-β, Wnt/β-catenin, PI3K/AKT, Notch, HER2-HER3, and JAK/STAT, orchestrate these processes, enabling tumour cells to adapt to the neural niche and evade immune surveillance.

A major focus is placed on the brain microenvironment, where astrocytes, microglia, and neurons interact with metastatic cells through gap junctions, cytokine signalling, and metabolic coupling.

These interactions create a supportive niche that promotes tumour survival and resistance to therapy.

The authors also evaluate current preclinical models, including intracardiac injection, orthotopic brain injection, patient-derived xenografts, and organoids, and highlight their strengths and limitations in recapitulating human BCBrM.

Emerging approaches such as humanised mouse models and advanced imaging techniques are paving the way for more translational research.

On the therapeutic front, the review discusses the limited efficacy of conventional treatments and the promise of CNS-penetrant agents like tucatinib, neratinib, and antibody-drug conjugates such as trastuzumab deruxtecan.

Immunotherapy, nanoparticle-based delivery, and focused ultrasound are also explored as strategies to overcome the blood-brain barrier.

Finally, the authors call for cross-disciplinary collaboration, innovative clinical trial designs, and personalised treatment strategies to improve outcomes and quality of life for patients with BCBrM.

Article: Breast Cancer Brain Metastasis: Bridging Biological Mechanisms to Therapeutic Innovations

Source: Sichuan International Medical Exchange and Promotion Association