Cancer Antigen 15-3 (CA 15-3): A Paradigm of Biomarker Utility in Oncology

Cancer Antigen 15-3 (CA 15-3), a derivative of the MUC1 mucin, epitomizes the intricate interplay between tumor biology and clinical diagnostics. This high-molecular-weight glycoprotein, characterized by aberrant glycosylation, serves as a crucial biomarker in the surveillance of breast cancer. This review delves into the molecular intricacies of CA 15-3, elucidates the methodologies employed in its purification, and highlights its clinical applications. Challenges in assay standardization and the burgeoning role of advanced technologies in refining its diagnostic accuracy are also explored, offering a comprehensive discourse on this pivotal biomarker.