细胞外囊泡（EVs）是纳米级的细胞外颗粒，因携带各种生物分子如核酸和蛋白质以及参与细胞间信息交换而受到广泛的科学关注，由于其潜在的诊断价值，成为研究热点。乳腺癌是妇女癌症相关死亡的主要原因，大约90％的患者死亡是由于转移的并发症。脑转移是乳腺癌患者死亡的重要原因，约10-15％的乳腺癌患者会出现脑转移。因此，早期预防脑转移和研发新治疗方法至关重要。已经发现小型EVs参与了乳腺癌脑转移（BCBM）的整个过程，在推动器官特异性转移，形成预转移微环境，破坏血脑屏障和促进转移性肿瘤细胞增殖方面发挥了重要作用。我们总结了小型EVs在上述病理过程中在细胞和分子水平上的作用机制，并期待其在乳腺癌脑转移治疗中的潜在应用，希望为乳腺癌脑转移的精确治疗提供新思路。版权所有©2023罗，康，刘，李和李。

Extracellular vesicles (EVs) are nanoscale extracellular particles that have received widespread scientific attention for carrying a variety of biomolecules such as nucleic acids and proteins and participating in the process of intercellular information exchange, making them become a research hotspot due to their potential diagnostic value. Breast cancer is the leading cause of cancer-related death in women, approximately 90% of patient deaths are due to metastasis complications. Brain metastasis is an important cause of mortality in breast cancer patients, about 10-15% of breast cancer patients will develop brain metastasis. Therefore, early prevention of brain metastasis and the development of new treatments are crucial. Small EVs have been discovered to be involved in the entire process of breast cancer brain metastasis (BCBM), playing an important role in driving organ-specific metastasis, forming pre-metastatic niches, disrupting the blood-brain barrier, and promoting metastatic tumor cell proliferation. We summarize the mechanisms of small EVs in the aforementioned pathological processes at the cellular and molecular levels, and anticipate their potential applications in the treatment of breast cancer brain metastasis, with the hope of providing new ideas for the precise treatment of breast cancer brain metastasis.Copyright © 2023 Luo, Kang, Liu, Li and Li.