Antigen CA 15-3 (mammary gland)

Carbohydrate antigen CA 15-3 specific protein is an oncomarker of breast cancer. The antigen is produced in small amounts in a healthy body by the cells of the ducts of the breast. If oncological processes occur in the gland, then an abnormally high production of CA 15-3 occurs. Thus, the test is used to diagnose breast tumors not only when there are signs of the disease, but also at the stage of preclinical manifestations.

CA 15-3 cannot be used to diagnose breast cancer, but it allows you to identify a special risk group from the entire number of patients who need the next stage of a more detailed diagnosis. Therefore, the method is considered screening. Observation of the concentration in dynamics is much more informative than a single determination of CA 15-3: the antigen increases with the tumor and with the appearance of metastases.

If after the course of therapy the oncomarker practically disappeared - this is a good prognostic sign, and on the contrary, the appearance of CA 15-3 after treatment indicates the relapse of the disease or the presence of metastases. If the doctor suspects a gland tumor, and the oncomarker does not exceed the acceptable norm - it does not exclude the diagnosis, because in some cases cancer cells at the initial stage of the disease may not synthesize CA 15-3.

If the level of CA 15-3 is high, however, other analysis do not confirm the presence of breast cancer, in this case it is necessary to look for pathology in other organs: intestine, liver, ovaries or uterus.

Read also: "What oncomarkers can tell you", "Women's cancer profile", "10 main cancer symptoms worth knowing about"