Claudin 低乳腺癌 (CLBC) 是 2007 年在分子水平上发现的乳腺癌亚组。Claudin 是构成紧密连接的主要蛋白质之一，在抗炎和抗肿瘤反应以及维持水和电解质平衡。紧密连接蛋白表达的减少会导致紧密连接结构的破坏和下游信号通路的激活，从而导致肿瘤的形成。 Claudin-low乳腺癌的起源仍存在争议。 Claudin 低乳腺癌的特点是 Claudin3、4、7、E-cadherin 和 HER2 低表达，Vimentin、Snai 1/2、Twist 1/2、Zeb 1/2 和 ALDH1 高表达，以及干细胞特征。 Claudin-low乳腺癌临床发病多在绝经年龄，组织学分级较高。这种乳腺癌亚型比其他亚型更容易扩散到淋巴结。克劳丁低乳腺癌常常伴有侵袭性增加和预后不良。根据临床回顾性分析，claudin-low乳腺癌可以实现低病理完全缓解。目前，虽然已经确定了claudin-low乳腺癌的多个治疗靶点，但有效的治疗仍处于基础研究阶段，尚未设计动物研究或临床试验。本文广泛讨论了 CLBC 的起源、分子生物学特征、病理特征、治疗和预后。这将有助于全面了解 CLBC，并为乳腺癌个体化治疗奠定基础。版权所有 © 2023 Pan、Xu、Ma、Yao、Zhao、Wang 和 Chen。

Claudin-low breast cancer (CLBC) is a subgroup of breast cancer discovered at the molecular level in 2007. Claudin is one of the primary proteins that make up tight junctions, and it plays crucial roles in anti-inflammatory and antitumor responses as well as the maintenance of water and electrolyte balance. Decreased expression of claudin results in the disruption of tight junction structures and the activation of downstream signaling pathways, which can lead to tumor formation. The origin of Claudin-low breast cancer is still in dispute. Claudin-low breast cancer is characterized by low expression of Claudin3, 4, 7, E-cadherin, and HER2 and high expression of Vimentin, Snai 1/2, Twist 1/2, Zeb 1/2, and ALDH1, as well as stem cell characteristics. The clinical onset of claudin-low breast cancer is at menopause age, and its histological grade is higher. This subtype of breast cancer is more likely to spread to lymph nodes than other subtypes. Claudin-low breast cancer is frequently accompanied by increased invasiveness and a poor prognosis. According to a clinical retrospective analysis, claudin-low breast cancer can achieve low pathological complete remission. At present, although several therapeutic targets of claudin-low breast cancer have been identified, the effective treatment remains in basic research stages, and no animal studies or clinical trials have been designed. The origin, molecular biological characteristics, pathological characteristics, treatment, and prognosis of CLBC are extensively discussed in this article. This will contribute to a comprehensive understanding of CLBC and serve as the foundation for the individualization of breast cancer treatment.Copyright © 2023 Pan, Xu, Ma, Yao, Zhao, Wang and Chen.