A detailed view of a blood sample being analysed for the Tumour Markers Female Blood Test.

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Demystifying CA125

CA125 stands for Cancer Antigen 125. It is a protein found on the surface of many ovarian cancer cells, but it is also present on normal cells in the ovaries, fallopian tubes, and the lining of the abdomen and chest. A CA125 test measures the amount of this protein in the blood.

It is vital to understand that a raised CA125 level is not a definitive diagnosis of cancer. The National Institute for Health and Care Excellence (NICE) guidelines highlight that CA125 levels can fluctuate and be elevated due to a variety of benign, non-cancerous conditions. [1]

Benign Causes of Elevated CA125

Many common gynaecological and general health conditions can cause CA125 levels to rise. These include:

Endometriosis: A condition where tissue similar to the lining of the womb grows elsewhere in the body.
Fibroids: Non-cancerous growths in or around the womb.
Pelvic Inflammatory Disease (PID): An infection of the female reproductive system.
Menstruation: CA125 levels can naturally rise during a woman’s period.
Pregnancy: Levels can also be elevated during pregnancy.

Because of these numerous benign causes, CA125 is considered to have a high rate of “false positives” if used in isolation as a screening tool for the general population. [2]

How CA125 is Used Clinically

Despite its limitations as a standalone diagnostic tool, CA125 is highly valuable when used correctly within a clinical context. It is most often used in two main ways:

Assessment of Symptoms: If a woman presents with symptoms that could suggest an ovarian issue, such as persistent bloating, pelvic pain, or feeling full quickly, a doctor may order a CA125 test as part of the initial investigation. [1]
Monitoring: For women who have already been diagnosed with certain conditions, tracking CA125 levels over time can help monitor the effectiveness of treatment or check for recurrence.

A Piece of the Puzzle

The key takeaway is that CA125 is just one piece of information. It can help provide insight and guide further investigations, such as ultrasound scans, but it should always be interpreted by a healthcare professional in the context of a woman’s overall health, symptoms, and medical history.

For those looking to gain a broader understanding of their health baseline, comprehensive testing that includes markers like CA125 can be a useful starting point. The Tumour Markers (Female) Blood Test from Clinilabs includes CA125, offering a detailed look at this and other important indicators. This information can support informed conversations with a healthcare professional, helping you to take a proactive and empowered approach to your wellbeing.