CA 15-3 blood test in Chiswick

What the test measures

CA 15-3 is a protein released from the surface of breast cells and some other tissues. Specialists mainly use it to track how a known breast cancer is responding to treatment, or to watch for changes over time in people who have already been treated. It is one of several tumour-associated markers and is interpreted as part of a wider plan of care.

CA 15-3 is not a screening test for breast cancer and cannot be used to check whether you have it. Many early breast cancers do not raise the level, while benign breast conditions, liver disease, lung conditions, pregnancy and some autoimmune conditions can raise it. Breast screening in the UK is carried out through mammograms in the NHS Breast Screening Programme. The price includes the blood sample taken at our Chiswick clinic, analysis at the Randox accredited laboratory, a review of your result with an Omnia practitioner and a GP feedback report on request.

Who it is for

• You have been treated for breast cancer and your oncology team uses CA 15-3 to follow your progress.
• You would like to repeat a CA 15-3 result that your specialist has been tracking.
• You want a practitioner to explain what CA 15-3 can and cannot tell you before deciding whether to test.
• You are building a wider picture of health with a clinician and CA 15-3 has been suggested for a specific reason.

Understanding your result

Your report shows your CA 15-3 with the laboratory reference range. In monitoring, a steady trend over several results is usually more meaningful than a single value, and your specialist will compare results with imaging and your clinical progress. In someone without a breast cancer diagnosis, a raised level is most often due to another cause and needs medical review.

A normal level does not rule out breast cancer, so any breast lump, skin or nipple change should be seen by your GP. A figure outside the range simply flags something to discuss, rather than confirming a condition.

Preparing for your test

No fasting is required for this test. Let us know if you are pregnant or breastfeeding, and about any known liver or lung condition. Please stop biotin or high-dose hair, skin and nail supplements for 48 hours before your sample to avoid interference with the laboratory method.

CA 15-3 is included in Omnia Signature, our most comprehensive health check. Our hub sets out every blood test and price in Chiswick, or look up individual markers in the biomarker A to Z.

Questions

How much is a CA 15-3 blood test in Chiswick?

The CA 15-3 blood test costs £59. The price includes your sample at our Chiswick clinic, laboratory analysis, a practitioner review and a GP feedback report on request.

Is CA 15-3 a breast cancer test?

No. It is a tumour-associated marker used mainly to monitor known breast cancer. It cannot screen for or rule out breast cancer, and benign conditions can raise it.

How often is CA 15-3 checked?

That depends on your treatment plan, which is decided by your oncology team. If you are testing privately, it is helpful to share results with them.

What should I do if I notice a breast change?

See your GP promptly. A lump, change in shape, skin dimpling or nipple change needs a clinical examination, whatever a blood test shows.