CA15-3

Carbohydrate antigen 15-3 (CA15-3) is a mucinous glycoprotein that normally exists in various secretory epithelial cells. It has lubricating and protective effects on the respiratory tract, digestive tract, and reproductive tract. Some research found that CA15-3 is not or lowly expressed in benign tumors such as breast fibroadenoma and intraductal papilloma, but highly expressed in malignant tumors. Therefore, it has become an important biomarker for clinical diagnosis of breast cancer. Moreover, CA15-3 positivity rate in invasive cancer is significantly higher than that in situ cancer, and its expression level is up-regulated with the increased tumor pathological grading, which has reference value for prognosis evaluation and recurrence monitoring. Meanwhile, some scholars pointed out that CA15-3 can be used for distinguishing extramammary Paget's disease (+) from Bowen's disease (-) and malignant melanoma (-), and its co-expression in sweat glands suggests that the occurrence of the disease may be related to sweat glands. In addition, CA15-3 is expressed in thyroid cancer, pancreatic cancer, lung cancer, liver cancer, stomach cancer, colorectal cancer and other tumors.