A cross-sectional study on the expression of CD44 as a stem cell marker in breast cancer patients: Association with clinicopathological prognostic markers across molecular subtypes.

The clinical application of cancer stem cell marker CD44 in breast cancer prognosis has been widely explored. However, data on the association between CD44 expression and prognostication across molecular subtypes of breast cancer remain limited. In this study we evaluated CD44 expression in various breast carcinoma subtypes and its association with clinicopathological prognostic parameters. Further, molecular docking studies were performed to investigate molecular interactions involving CD44. A cross-sectional study was conducted on breast tissue specimens collected from 60 patients over a period of two years. Immunohistochemistry analyses were performed to assess CD44 expression in paraffin-embedded breast tissue samples. Clinicopathological prognostic parameters were analysed in relation to CD44 expression. Of the 60 cases, CD44 staining was positive in 34 cases (57%) and negative in 26 (43%). Increased CD44 expression was correlated with histological grade (p=0.022), lymphovascular invasion (p=0.039), and lymph node status (p=0.033) in invasive breast carcinoma. Notably, high CD44 expression was also observed in patients with triple-negative breast cancer. Further, protein docking analysis revealed significant interactions between CD44 and molecular markers such as ER, PR, HER2/neu, and Ki-67, with HER2/neu showing the strongest correlation. Several new targeted treatments for breast cancer were also identified through docking studies. These findings highlight that induced CD44 expression could be a potential marker of aggressive tumour behaviour in invasive breast carcinoma and across multiple molecular subtypes, including triple-negative breast cancer.