Description
Overview: Cancer Antigen 15-3 (CA 15-3) is a protein produced by normal breast cells. In many people with breast cancer, the production of this antigen increases significantly, shedding into the bloodstream. While it is the most widely used marker for breast cancer, it is generally not used for early screening because levels are rarely elevated in the early stages of the disease.
Clinical Significance:
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Monitoring Metastasis: It is most useful for patients with Stage IV (metastatic) breast cancer. Rising levels often indicate the cancer is growing or spreading, while falling levels suggest the treatment is working.
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Recurrence Detection: For patients who have finished treatment, a rise in CA 15-3 can be an early warning sign that the cancer has returned, sometimes months before symptoms appear.
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Benign Conditions: Mild elevations can occur in non-cancerous conditions like liver disease, benign breast conditions, or pregnancy, which is why it must be interpreted by a specialist.
When is this test recommended?
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For patients currently undergoing treatment for invasive or metastatic breast cancer.
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Periodically after treatment to monitor for recurrence (relapse).
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It is not recommended as a screening test for healthy women without symptoms.
Sample Requirements:
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Specimen: Serum (Blood).
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Container: Gold Top (SST) or Red Top Tube.
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Preparation: No special preparation or fasting is required.
