Distribution of CD44⁺/CD24^-/low cells in different molecular subtypes of breast cancer tissues and its clinical significance

Objective To investigate the distribution of CD44⁺/CD24^-/low cells in different molecular subtypes of breast cancer tissues and its clinical significance. Methods The expression of CD44 and CD24 in 199 breast cancer tissues was simultaneously detected by double-staining immunohistochemistry. The association of CD44 and CD24 expression in different molecular types of breast cancer tissues with clinical pathological characteristics and prognosis was analyzed. Results The positive rates of CD44 and CD24 were higher in breast cancer tissues of subtypes Luminal A (82.5%) and HER2 overexpression (69.0%), respectively. The phenotype of CD44⁺/CD24^-/low was associated with patient age (P=0.0444), and the presence of lymph node metastasis (P=0.0377). Conclusions CD44 is highly expressed in breast cancer tissues of type Luminal A. No statistical difference was found in CD24 expression among different molecular subtypes of breast cancer tissues. There was no statistical difference in CD44⁺/CD24^-/low phenotype among different molecular subtypes of breast cancer tissues. Meanwhile, CD44⁺/CD24^-/low is closely associated with lymph node metastasis, which suggests that CD44⁺/CD24^-/low is an influencing factor of lymph node metastasis independent of the molecular types of breast cancer.