CA 15-3 antigen is a "mucin-like, high molecular weight, mainly released by breast carcinoma cells.
CA 15-3 is defined by its reaction with two monoclonal antibodies:
one of them (115D8) binds to an antigen in human milk;
another (DF3) binds to a membrane fraction of carcinoma cells.
In healthy people were determined low serum levels less than 30 U / ml.
CA 15-3 physiological slight increases are recorded in 4-7% of women breastfeeding and about 8% of pregnant women.
The main indication consists of CA 15-3 in monitoring therapy, diagnosis and detection of metastases appellants in breast carcinoma. Elevated CA 15-3 correlated with tumor mass, are found in approximately 70% of patients with metastatic breast carcinoma, but only 40% in cases without metastasis.
Quantitatively, secretion of CA 15-3 is independent of hormone receptors (estrogen, progesterone) and histological form.
Mild and transient increases in CA 15-3 is also found in lung carcinoma, ovarian, endometrial, gastric, pancreatic, colorectal.
Slightly increased values were recorded in benign conditions: hepatitis, liver cirrhosis, kidney, lung, ovarian, breast (mastopatie, fibroadenom).