Cancer Antigen (CA) 15-3 Blood Test
This Cancer Antigen (CA) 15-3 Blood Test is used for monitoring the response to invasive breast cancer treatment and monitoring the recurrence of the disease.
CA 15- 3 is an antigen or a substance that stimulates the defense system of your body. Some cancer cell types release antigen CA 15- 3 into the blood. This test is used to track certain cancers. CA 15-3 is not used as a screening test or a diagnostic test to find breast cancer.
Breast cancer is the cancer that most likely releases CA 15-3, particularly after treatment with breast cancer. Antigens like CA 15-3 that provide cancer information are called tumor markers.
This test may be needed if:
A diagnosis of breast cancer has been made, and monitoring of treatment is necessary.
Treatment of breast cancer is completed, and confirmation is needed to find out if the cancer has come back or spread.
It is important to know that having a positive blood test for CA 15-3 does not mean that you have breast cancer or that your breast cancer has returned. Additional conditions can lead to CA 15-3 in your blood. Non-cancerous breast, ovary and liver conditions can lead to an increase in CA 15- 3.
In general, increased values can indicate the progression or recurrence of the disease. Decreasing values may mean the regression of the disease.
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