PSA testing for prostate cancer

The PSA test is a blood test that can help suggest if you have prostate cancer. It measures the amount of a protein called prostate specific antigen (PSA). This protein is produced by both normal and cancerous prostate cells. A raised level of PSA may be a sign of cancer.

But the test is not perfect. So, it’s important to understand and think about the risks, as well as the benefits, before you decide whether to have PSA testing.

About PSA Testing

PSA is a protein that’s produced by your prostate gland. If you have a prostate gland, it’s normal to have a small amount of PSA in your blood. Your PSA level rises as you get older, and your prostate gets bigger.

If you have prostate cancer, this can raise the level of PSA in your blood. A PSA test can detect this. But it’s important to bear in mind that a raised PSA level can be caused by something other than cancer. There are some much less serious causes of raised PSA. These include:

• having an enlarged prostate (benign prostatic hyperplasia). This is a very common condition in older men
• urinary infections
• inflammation or infection of the prostate gland
• having a urinary catheter (a tube from your bladder to drain urine)
• recent vigorous exercise
• recent ejaculation

It’s also important to know that prostate cancer doesn’t always raise PSA. Around one in seven men with prostate cancer will not have a raised PSA.

Prostate cancer doesn’t always cause symptoms and it becomes more common as you get older. Although prostate cancer causes problems for some people, others live with it for many years without any major problems.

Who can have a PSA test?

If you have symptoms

Your doctor may offer you a PSA test if you have symptoms that could be caused by problems with your prostate. These symptoms may include:

• having to keep getting up at night to pee
• having to pee more often
• difficulty in starting to pee
• needing to pee more urgently
• not being able to pee when you really need to
• feeling that you haven’t emptied your bladder fully
• dribbling after you pee
• blood in your pee

A PSA test may also be offered if you have other symptoms which your doctor feels might be due to prostate cancer, such as problems getting an erection

If you have no symptoms (screeing)

PSA testing isn’t part of a national screening programme for prostate cancer. This is because we don’t know if the benefits of the test outweigh the risks. Instead, you can decide for yourself whether to have your PSA level checked once you are 50. This is called the Prostate Cancer Risk Management Programme.

So even if you don’t have symptoms, if you’re 50 or over, you can request a PSA test at your doctor surgery. But it’s important to think about the benefits and risks of having the test, and its limitations. Your doctor should give you detailed information about the pros and cons of the test to help you think this through. They’ll also discuss other tests you would be advised to have following a raised PSA result. Your doctor will be able to discuss what treatments you may need if you’re diagnosed with prostate cancer. Talking to your doctor will help you make an informed decision about whether to have the PSA test.

What are the benefits and risk of a PSA test?

Benefits and risks

Before offering you a PSA test, your doctor should talk to you about the benefits and risks of having the test. We summarise some of the main points here.

Benefits

• If you have a normal result, it may help to reassure you.
• If you have a prostate cancer that could go on to cause problems, the PSA test can help to diagnose it at an early stage.
• Being diagnosed early means you can get treatment earlier when it will be most beneficial.
• PSA testing can be useful for monitoring you if you’ve been diagnosed with prostate cancer and are under surveillance or having treatment.

Risks

• You may get a normal PSA result even if you do have cancer (a false negative). This can provide false reassurance reassurance. But these are often low grade (less harmful) cancers and may not all be ones that go on to cause problems.
• You may have a raised PSA result even if you don’t have prostate cancer (a false positive). This can cause unnecessary anxiety. It may mean you end up going for unnecessary invasive tests which themselves can cause side-effects.
• You may be diagnosed with a very slow-growing cancer that would never have caused problems. So, you may end up having treatment for your cancer that isn’t really necessary.

Everyone will value these benefits and risks differently. Your decision about having the test will depend on your own feelings and preferences.

Having a PSA test

If you decide to go ahead with the test, your doctor will ask you to book a blood test at a suitable time. You should be able to have a PSA test at your doctor surgery.

You should not have the PSA test if you:

• have an active urine infection
• have had a prostate biopsy within the last six weeks
• have had a rectal examination within the last week
• have done vigorous exercise within the last two days
• have ejaculated within the last two days

If your sex life includes you having your prostate stimulated, or being the receptive partner in anal sex, try to avoid these for a week before your test. All these things can raise your PSA level and so may give an inaccurate result.

Your doctor may also suggest you have a rectal examination after your blood test. Your doctor or nurse will gently feel inside your back passage (rectum). They are checking for any hard or irregular areas that could be a sign of prostate cancer. Together with the PSA test, this helps your doctor decide whether to offer you a referral for further tests. These further tests may include an MRI scan and then possibly a biopsy. 

Your PSA test results

When will i get the results of my PSA test?

It can take around a week to get the results of your PSA test, although your doctor surgery may differ slightly from this.

What is a high level of PSA?

PSA is measured in nanograms per millilitre of blood (ng/ml). The level that’s considered normal depends on your age and ethnicity. If you’re aged 50 to 69, your PSA level is considered to be raised if it’s 3.0ng/ml or higher. However, this is just a guide. As you get older, your prostate gets bigger and your PSA level rises. It can also be affected by a urinary infection or vigorous exercise (for more information, see our section: Having a PSA test).

What happens if I have a high PSA level?

If you have a high PSA level, your doctor will refer you to a urological cancer specialist. You can usually expect to be seen within two weeks. In some cases, your doctor may repeat the PSA test first, before referring you. Remember, PSA level alone can’t show for sure if you have prostate cancer. Your doctor will look at several other factors as well to decide whether you need further tests. These will include results of your rectal examination, if you’ve had one. And your doctor will also take into account whether you have risk factors for prostate cancer. These include your age, your family history and your ethnicity.

If your PSA level is normal, your doctor may sometimes still wish to refer you to a specialist. This may be because your rectal examination showed something abnormal, or you’re at high risk of prostate cancer.

Your doctor might ask you to repeat the test if your PSA level is borderline or just above normal. They may also want you to repeat the test if there’s something that could have affected the result. This could include having a recent infection.