Exploring research progress in studying serum exosomal miRNA-21 as a molecular diagnostic marker for breast cancer

Breast cancer is one of the most prevalent malignancies affecting women globally and poses a significant public health challenge. Early clinical detection plays a pivotal role in providing optimal treatment opportunities and favorable prognoses, crucial for reducing breast cancer mortality and enhancing patients' quality of life. Therefore, the timely identification and diagnosis of breast cancer are imperative. Conventional tumor markers, such as carcinoembryonic antigen (CEA) and carbohydrate antigen 15-3 (CA15-3), serve as reliable methods for actively monitoring disease progression and have become a routine auxiliary diagnostic approach in clinical settings. However, these biomarkers exhibit limitations in sensitivity and specificity, particularly in the early screening and diagnosis of tumors, often yielding results inconsistent with clinical manifestations. In recent years, research has increasingly focused on exosomes released by tumor cells as potential new biomarkers for early stage breast cancer screening. Exosomes carry various components, including tumor-derived proteins, nucleic acids, and lipids. This paper delves into the specific utilization of serum exosomal microRNA-21 (miR-21) as a biomarker for early detection and diagnosis of breast cancer, evaluating its efficacy within this framework.