Every year, around 57,900 men in the UK are diagnosed with prostate cancer – around 160 cases a day. Around 1 in 6 men in the UK will be diagnosed with prostate cancer in their lifetime, according to Cancer Research UK.
A PSA blood test is a key step towards diagnosis, which ultimately requires a prostate biopsy. However, PSA levels can be raised by several other prostate conditions. So, when do you really need an invasive biopsy? This is where knowing your free PSA ratio can help.
Here, we’ll explore what the free to total ratio of PSA is and its role in determining the onward management of patients including those who need a biopsy.
What is PSA?
PSA or prostate specific antigen is a protein that’s produced by the prostate gland in men. It thins out semen after ejaculation. This allows the sperm in semen to swim more easily. Small amounts of PSA in the blood are, therefore, normal, and PSA levels naturally rise with age.
However, high levels of PSA can be a sign of a prostate condition. This includes prostate cancer, an enlarged prostate (also known as benign prostatic hyperplasia (BPH)) and prostatitis. A urinary tract infection (infection of the urethra or bladder) can also cause higher levels of PSA.
In the UK, there’s no national prostate cancer screening programme. However, PSA testing is recommended on the NHS, especially if you have symptoms (routine PSA testing should be offered).However, PSA testing is recommended on the NHS if you have symptoms that could suggest you have prostate cancer.
Men aged over 50 without symptoms can talk to their NHS GP about having a free PSA test. This is part of the NHS Prostate Cancer Risk Management Programme (PCRMP).
At Vista Health, you can access a private PSA test if you are a man of any age with or without symptoms, and without the need for a GP referral.
Understanding PSA tests: total vs free PSA
The different forms of prostate specific antigen (PSA)
PSA in your blood comes in 2 forms:
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PSA that is not attached to any other proteins, which is called free PSA or unbound PSA.
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PSA that is attached to other proteins, which is called bound PSA.
Your total PSA level is a measure of both free and bound PSA.
A standard PSA test measures your total PSA levels. A free-to-total PSA test measures your total PSA levels and free PSA levels.
Why both tests matter in prostate health
The first test performed to investigate your PSA levels is usually a standard PSA test. If it shows that you have high PSA levels, this could be due to several different conditions affecting the prostate or urinary system.
Your doctor may then recommend that you have a free-to-total PSA test. This calculates the ratio of free PSA to total PSA.
If your total PSA levels are high and your free PSA levels are high, you are more likely to have benign prostatic hyperplasia (an enlarged prostate). Although you may still need other tests, this result reduces the likelihood that you will need a prostate biopsy, which most men find to be a cause of anxiety.
In prostate cancer, PSA is more often bound to other proteins. So, if your total PSA levels are high and your free PSA levels are low, there is a higher probability that you have prostate cancer. This test result does not confirm a diagnosis of prostate cancer, but it suggests that you need further testing.
Further tests to help determine if you have prostate cancer may include a physical examination called a digital rectal examination (DRE), a prostate MRI scan and/or a prostate biopsy. Prostate biopsy plays a vital role in the diagnosis of prostate cancer.
Understanding your PSA test results
Total PSA test
A PSA blood test measures PSA levels in nanograms (ng) per millilitre (ml) of blood. Your test results will be compared to reference ranges for what is normal for someone of your age. This is because PSA levels are higher in older men.
Free-to-total PSA ratio
When the free-to-total PSA ratio is calculated, a percentage free PSA of 10% or less usually means that the patient should be reviewed by a Urologist, who may consider a biopsy.
If the percentage free PSA is between 10 and 25%, a biopsy may still be suggested depending on other risk factors.
What happens after a diagnosis of prostate cancer
Urologists (doctors who specialise in treating the urinary system and male reproductive system) are involved in diagnosing prostate cancer.
If your PSA test combined with further tests confirm that you have prostate cancer, you will additionally be cared for by specialists in oncology (cancer). Your doctors will discuss your treatment options with you.
Depending on the type of prostate cancer and how quickly it is progressing, you may need active surveillance or treatment, such as hormone therapy, surgery, radiotherapy and/or chemotherapy.
Get clarity on your PSA levels
If you have a family history of prostate cancer or are concerned about your prostate health, a private PSA test with Vista Health alongside expert clinical insights can help provide reassurance.
We aim to send you a report with your results within 3 working days of the lab receiving your test samples. You can then discuss your results with your NHS GP or an experienced Vista Health GP.
To get clarity on your PSA levels with an at-home PSA test, simply purchase our Vista Health Male Cancer Screen kit, which comes with simple, clear instructions.
Sources
https://tgfct.org.uk/Testing-and-Treatments/PSA-Testing/Free-to-Total
https://www.cancer.org/cancer/types/prostate-cancer/detection-diagnosis-staging/tests.html
https://www.prostate.org.au/testing-and-diagnosis/psa-testing/free-to-total-psa-testing/
https://www.health.harvard.edu/blog/what-is-the-difference-between-psa-and-free-psa-20091001123
https://www.nwlpathology.nhs.uk/test/prostate-specific-antigen-psa-percentage-free/