脑转移（BM）是乳腺癌（BC）常见而且毁灭性的表现。BM特别在HER2阳性和三阴性乳腺癌表型中频繁出现，通常发生在转移性扩散到颅外部位之后。过去十年中，已经报道了几种介导BM和预测BC风险的生物标记物的基因。这些发现推进了对BM病理生物学的理解，并为发展新的治疗策略铺平了道路，但仍需要彻底的临床验证。因此，更好地了解BM的机制方面，以及肿瘤细胞与大脑微环境相互作用的区分是至关重要的。本文讨论了转移级联的分子基础：上皮间质转化，癌症和肿瘤微环境相互作用和内皮细胞内粘连，大脑新巢穴的准备以及在新地点的生存。我们还概述了乳腺癌细胞脑向性机制的假定。最后，我们讨论了预测来自BC的BM的生物标记物领域的进展（组织和液体为基础）。版权所有©2023 Elsevier Ltd.。

Brain metastases (BM) are a common and devastating manifestation of breast cancer (BC). BM are particularly frequent in the HER2-positive and triple-negative breast cancer phenotypes and usually occur following the metastatic spread to extracranial sites. Several genes mediating BM and biomarkers predicting their risk in BC have been reported in the past decade. These findings have advanced the understanding of BM pathobiology and paved the way for developing new therapeutic strategies but they still warrant a thorough clinical validation. Hence, a better understanding of the mechanistic aspects of BM and delineating the interactions of tumor cells with the brain microenvironment are of utmost importance. This review discusses the molecular basis of the metastatic cascade: the epithelial-mesenchymal transition, cancer, and tumor microenvironment interaction and intravasation, priming of the metastatic niche in the brain, and survival in the new site. We also outline the postulated mechanisms of BC cells' brain tropism. Finally, we discuss advances in the field of biomarkers (both tissue-based and liquid-based) that predict BM from BC.Copyright © 2023 Elsevier Ltd. All rights reserved.