Cancer Antigen 15-3
Private Cancer Antigen 15-3 blood test in London for £144, measuring one breast tumour marker with results expected in approximately 1 business day.
Turnaround time
1 business day
Biomarkers count
1
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Overview of the Cancer Antigen 15-3
The Cancer Antigen 15-3 blood test measures Cancer Antigen 15-3, commonly abbreviated to CA 15-3, a tumour-associated marker most commonly used in the management of breast cancer.
CA 15-3 is associated with a protein produced by breast epithelial cells and may become elevated when certain breast cancers release increased amounts into the bloodstream.
The test contains 1 biomarker: Cancer Antigen 15-3.
CA 15-3 should not be used as a general breast cancer screening test and cannot replace mammography, breast examination, ultrasound, biopsy or other diagnostic investigations.
Many people with early breast cancer have normal CA 15-3 levels. Even in advanced breast cancer, some tumours do not produce significant amounts of the marker.
Its principal value is therefore in selected people with previously diagnosed breast cancer, particularly where CA 15-3 was elevated at baseline and can be followed over time.
Serial measurements can support assessment of treatment response and disease activity. Falling values may accompany effective treatment, while increasing levels can lead to further clinical or imaging assessment.
CA 15-3 can also be elevated in other cancers and in several non-malignant conditions, so an isolated raised result cannot diagnose breast cancer or recurrence.
What Does the Cancer Antigen 15-3 Test Check?
This test measures 1 biomarker.
Cancer Antigen 15-3
Measures CA 15-3, a tumour-associated marker used primarily for monitoring selected people with known breast cancer. The result is generally interpreted as a trend alongside imaging, treatment history and clinical findings rather than being used for cancer screening or standalone diagnosis.
Who May Benefit From the Cancer Antigen 15-3 Test?
This test may be suitable for people with known breast cancer where CA 15-3 has been specifically requested as part of specialist monitoring.
Known metastatic breast cancer - CA 15-3 can provide additional information about disease activity where the tumour produces the marker.
Monitoring breast cancer treatment - Serial measurements may help assess biochemical response alongside imaging and clinical examination.
Previously elevated CA 15-3 - A marker that was raised before treatment may be useful for subsequent comparison.
Follow-up after treatment - Specialists may request CA 15-3 in selected patients as part of structured follow-up.
Possible disease progression - Rising CA 15-3 during established cancer monitoring may prompt further clinical assessment or imaging.
Assessment of treatment response - Falling concentrations may accompany response to systemic treatment.
Monitoring advanced breast cancer - The marker has greater clinical utility in advanced disease than in early localised breast cancer.
Assessment alongside CEA - Some specialists use CA 15-3 alongside carcinoembryonic antigen during breast cancer monitoring.
Specialist-requested tumour marker testing - The test can be arranged privately where an oncologist, breast specialist or GP has specifically requested CA 15-3.
How to Prepare
Serial CA 15-3 measurements are generally more informative when compared using consistent clinical context and interpreted in relation to treatment dates.
Do not make decisions about cancer treatment on the basis of a CA 15-3 result without specialist review.
Symptoms and Reasons to Consider the Cancer Antigen 15-3 Test
The Cancer Antigen 15-3 test should not generally be requested solely because of breast symptoms. New breast symptoms require appropriate clinical assessment and imaging rather than relying on a tumour-marker blood test.
Known breast cancer with new symptoms - New clinical changes during follow-up may prompt repeat CA 15-3 alongside imaging and specialist review.
New unexplained bone pain in someone with known breast cancer - Persistent bone symptoms during cancer follow-up require clinical assessment and may lead to further investigations.
Unexplained weight loss during cancer follow-up - Significant changes may prompt reassessment of disease activity.
Persistent breathlessness in someone with known breast cancer - Respiratory symptoms require appropriate assessment and may lead to imaging rather than tumour-marker testing alone.
New neurological symptoms during cancer follow-up - These require prompt specialist assessment regardless of the CA 15-3 result.
Changing findings on imaging - A specialist may repeat CA 15-3 when imaging suggests a possible change in disease status.
Monitoring during systemic treatment - The marker may be repeated at intervals to evaluate trends alongside clinical and radiological response.
Previously rising CA 15-3 - Repeat measurement may help establish whether an earlier increase represents a sustained trend.
CA 15-3 is not a suitable investigation for deciding whether a new breast lump, nipple change or breast pain represents cancer.
Anyone with a new breast lump, nipple inversion, bloody nipple discharge, skin dimpling or another persistent breast change should undergo appropriate clinical breast assessment regardless of the tumour-marker result.
A normal CA 15-3 result does not exclude breast cancer or recurrence, and an elevated result does not independently prove that cancer is present or progressing.
How to Book Your Cancer Antigen 15-3 Test
Booking your Cancer Antigen 15-3 test with London Blood Tests is simple and designed to fit around your schedule.
Choose the Cancer Antigen 15-3
Select the Cancer Antigen 15-3 test online and review the included tumour marker before booking.
Select your sample collection option
Choose an in-clinic blood draw (+£35) or a home or hotel phlebotomy visit (+£60) where a qualified phlebotomist collects your sample.
Attend your appointment
A trained professional will collect your blood sample safely and efficiently at the clinic or during your arranged home or hotel visit.
Laboratory analysis
Your sample is sent to the laboratory, where Cancer Antigen 15-3 is measured using specialist tumour-marker analysis.
Receive your results securely
Your results are sent securely by email, ready to review yourself or discuss with an oncologist, breast specialist, GP or other suitably qualified healthcare professional.
When Will I Receive My Results?
The expected turnaround time for the Cancer Antigen 15-3 test is approximately 1 business day after your sample arrives at the laboratory.
Results are sent securely by email once laboratory analysis and authorisation are complete.
Additional laboratory checks or repeat analysis may occasionally extend the expected turnaround.
Understanding Your Results
Your Cancer Antigen 15-3 result shows the concentration of CA 15-3 in your blood according to the laboratory method and reference interval used.
A result within the reference interval does not exclude breast cancer.
CA 15-3 has limited sensitivity, particularly in early-stage breast cancer, and some advanced tumours do not produce significant amounts of the marker.
An elevated result may occur in advanced breast cancer and can sometimes correlate with overall disease burden.
However, CA 15-3 can also increase in other malignancies and in some non-cancerous conditions, including certain liver disorders and benign breast conditions.
An isolated elevated result therefore cannot diagnose breast cancer, metastatic disease or recurrence.
The test is most useful when a patient with established breast cancer has a known baseline value and subsequent measurements are compared over time.
Falling concentrations may accompany treatment response, while sustained rises can lead to additional clinical assessment.
Results should always be interpreted alongside imaging, treatment history, symptoms and specialist oncology review.
Why Book With London Blood Tests?
Private CA 15-3 testing in London - Access specialist Cancer Antigen 15-3 testing through London Blood Tests.
Targeted breast tumour-marker measurement - Measure CA 15-3 independently where it has been specifically requested.
Relevant to advanced breast cancer monitoring - CA 15-3 can provide additional information where a known breast tumour produces the marker.
Useful for treatment-response trends - Serial measurements may support assessment alongside imaging and clinical findings.
Relevant to specialist follow-up - CA 15-3 may form part of structured monitoring in selected patients with previously treated breast cancer.
Specialist laboratory analysis - Your sample is processed using dedicated tumour-marker testing methods.
Clinic and home visit options - Choose an in-clinic blood draw or arrange home or hotel phlebotomy depending on location and availability.
Secure results by email - Receive your authorised laboratory result securely once analysis is complete.
Clear pricing before booking - The Cancer Antigen 15-3 test is priced at £144, with sample collection charges shown separately.
Private Cancer Antigen 15-3 Blood Test in London
London Blood Tests provides the Cancer Antigen 15-3 blood test in London for people requiring targeted CA 15-3 measurement during specialist breast cancer monitoring.
The test costs £144 and measures one biomarker: Cancer Antigen 15-3.
CA 15-3 is principally used in people with known breast cancer, particularly advanced or metastatic disease where the tumour has previously produced the marker. It is not recommended as a general breast cancer screening test.
Clinic appointments are available alongside home and hotel phlebotomy depending on location and availability, providing flexible options for people looking for a private CA 15-3 blood test in London.
Results should be reviewed alongside imaging, previous CA 15-3 measurements, treatment history and specialist clinical assessment.