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.