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Cancer antigen CA-15-3 in the blood
Medical expert of the article
Last reviewed: 05.07.2025
Reference values (norm) of CA-15-3 concentration in blood serum are up to 27 IU/ml; in the third trimester of pregnancy – up to 40 IU/ml. Half-life is 7 days.
CA-15-3 is a membrane antigen of metastatic breast carcinoma cells. In healthy individuals, it can be detected on the epithelium of secreting cells and in secretions. CA-15-3 has a fairly high specificity for breast carcinoma compared to its benign diseases. Only occasionally is a slight increase in the marker (up to 50 IU/ml) detected in patients with liver cirrhosis. CA-15-3 is mainly used to monitor the course of the disease and the effectiveness of breast cancer treatment. In other tumors (ovarian, cervical and endometrial carcinoma), an increase in the marker level is observed only in the late stages of development.
Determination of CA-15-3 concentration is used to monitor treatment and diagnose recurrence of breast and lung cancer.
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