Description
The CA 15-3 blood test measures the level of Cancer Antigen 15-3, a tumor marker produced by certain cancer cells and released into the bloodstream. While it is not used to screen or diagnose breast cancer, it is an important tool for monitoring treatment response and detecting recurrence in individuals with invasive breast cancer.
Why the CA 15-3 Test Is Important
- Treatment Monitoring: CA 15-3 levels can indicate how well breast cancer treatment is working.
- Recurrence Detection: Regular monitoring can help detect whether the cancer has returned or spread after treatment.
- Supplemental Information: Elevated CA 15-3 levels do not automatically indicate cancer; conditions such as liver disease or benign breast conditions may also increase levels. Further evaluation is always necessary.
When the Test May Be Ordered
- After a breast cancer diagnosis to monitor treatment effectiveness.
- Following completion of breast cancer treatment to check for recurrence.
- Individuals experiencing breast-related symptoms, including:
- Lump in the breast
- Bloody nipple discharge
- Changes in breast or nipple shape or texture
- Redness or swollen lymph nodes
Understanding Abnormal Results
- High CA 15-3: May indicate the disease is worsening or has returned, but other conditions can also cause elevation.
- Low or Decreasing CA 15-3: May indicate improvement or a positive response to treatment.
It is essential to review results with a healthcare professional for proper interpretation and guidance.
Fasting: Not required.
