The PSA test is a blood test which can detect the early signs of prostate cancer.
The test, which can be done at a GP surgery, measures the level of PSA (prostate-specific antigen) in your blood.
PSA is made by the prostate gland. Some of it will leak into your blood, and the amount depends on your age and the health of your prostate.
Raised PSA levels
The amount of PSA in your blood is measured in nanograms of PSA per millilitre of blood (ng/ml). PSA levels can range from 1ng/ml to hundreds of ng/ml.
- If you're aged 50–59, your PSA level is considered raised if it's 3ng/ml or higher.
- If you're aged 60–69, your PSA level is considered raised if it's 4ng/ml or higher.
- If you're aged 70 or over, your PSA level is considered raised if it's 5ng/ml or higher.
A raised PSA level in your blood may show that you have a problem with your prostate. However, this may not be prostate cancer.
Other conditions, such as an enlarged prostate, prostatitis or a urinary infection, can also cause a raised PSA level.
All men over 50 are entitled to a PSA test free on the NHS, as long as they have made an informed choice based on the benefits, limitations and risks of having the test.
Your GP can discuss this choice with you, and can help you make a decision.
Men with a higher risk of prostate cancer, such as black men or men with a family history of the condition, may be encouraged to have a PSA test by their GP. Watch a video on black men and prostate cancer.
Before having the test
If you're having a PSA test, you should not have:
Each of these may give an inaccurate PSA reading.
What happens after the test?
There are usually three main options after a PSA test.
A normal PSA level
If your PSA level is not raised, you are unlikely to have cancer. No immediate action is needed, although you may have further PSA tests in the future. However, the PSA test doesn’t always pick up prostate cancer. Nearly one in seven men (15%) with a normal PSA level will have prostate cancer.
A slightly raised PSA level
Two out of three men with a raised PSA level will not have prostate cancer. If your PSA level is slightly higher than normal, you probably don’t have cancer but you might need further tests, including more PSA tests.
A raised PSA level
One out of three men with a raised PSA level will have cancer. The higher the level of PSA, the more likely it is to be a sign of cancer. If your PSA level is definitely raised, your GP will arrange for you to see a specialist for further tests to find out if you have prostate cancer.
A PSA test alone cannot tell you whether you have prostate cancer. If the test shows your PSA levels are raised, your doctor may suggest you have a digital rectal examination (DRE). This is an examination of the prostate gland, during which a doctor will insert a gloved finger into your rectum.
The DRE checks for signs of prostate cancer, such as the prostate gland feeling hard. However, a gland that feels normal does not necessarily mean you don't have cancer.
Many early cancers may not be detected by a DRE. Therefore, a DRE is not recommended as a substitute for the PSA test.
Your doctor will also consider your age, any family history of prostate cancer, your ethnic background and any previous PSA test results.
In some cases, extra PSA tests may help make the situation clearer or show any changes.
Pros and cons of the PSA test
Pros
- It may reassure you if the test result is normal.
- It may give you an indication of cancer before symptoms develop.
- It may find cancer at an early stage, when treatment could prevent the cancer from becoming more advanced.
- If treatment is successful, you will avoid the risks of advanced cancer.
- In cases of advanced cancer, treatment will usually extend life.
Cons
- It can miss cancer and provide false reassurance.
- It may lead to unnecessary worry and medical tests when there is no cancer.
- It cannot tell the difference between slow-growing and fast-growing cancer.
- It may make you worry by finding slow-growing cancer that may never cause any symptoms or shorten your life.
- To save one life from prostate cancer, 48 men would have to be treated.
Further tests
If your PSA level is raised, a biopsy, which involves taking tissue samples from the prostate gland, may be needed to check if you have cancer.
About two out of three men who have a biopsy of the prostate don’t have cancer.
However, biopsies can miss some cancers. Biopsies in one in five men will fail to pick up prostate cancer. You may not know for sure that you don’t have cancer after a clear result.
Biopsies can sometimes cause complications. About one in three men experience blood in the urine and blood in the sperm after a biopsy.
If the PSA test and biopsy show the early signs of cancer, talk to your consultant about the benefits and risks of any treatment before you begin.
Read more about prostate cancer treatment, including the side effects of different treatments.
