CA15-3 (Female) Test

CA15-3 (Female)

Cancer antigen 15-3 (CA 15-3) is a protein that is produced by normal breast cells. In many people with cancerous breast tumours, there is an increased production of CA 15-3 and the related cancer antigen 27.29. CA 15-3 does not cause cancer; rather, it is shed by the tumour cells and enters the blood. This test measures CA 15-3 in the blood. Since CA 15-3 can be measured in the blood, it is useful as a tumour marker to follow the course of the cancer.