Testing for prostate cancer

There is currently no screening programme for prostate cancer in the UK. This isbecause it has not been proved that the benefits would outweigh the risks.

PSA screening

Routinely screening all men to check their prostate-specific antigen (PSA) levels is a controversial subject in the international medical community.

There are several reasons for this:

• PSA tests are unreliable and can suggest prostate cancer when no cancer exists (a false-positive result). This means that many men often have invasive and sometimes painful biopsies for no reason. Also, up to 15% of men with prostate cancer have normal PSA levels (a false-negative result), so many cases may be missed.
• The PSA test can find aggressive prostate cancer that needs treatment, but it can also find slow-growing cancer that may never cause symptoms or shorten life. Some men may therefore face difficult decisions about treatment.
• Treating prostate cancer in its early stages can be beneficial in some cases. But theside effects of the various treatments are potentially so serious that men may choose to delay treatment until it is absolutely necessary.

• Although screening has been shown to reduce a man's chance of dying from prostate cancer, it would mean many menreceive treatment unnecessarily.

More research is needed to determine whether a screening programme would provide men with more benefit than harm.

One European study showed deaths from prostate cancer could be reduced by 20% if there was a screening programme, but this needs to be balanced against the harms of:

• overdiagnosispeople being diagnosed with a cancerthat will never cause symptoms or death during their lifetime
• overtreatmentpeople being treated unnecessarily for tumours that would beunlikely tobe harmful

To save one life from prostate cancer, 27 men would have to be diagnosed with it. A recent large study in America found no reduction in the number of deaths.

Improving the test

As there are many reasons why PSA levels may be high at any one time, researchers are trying to make the PSA test, or a variation of it, more accurate. This includes looking at how PSA levels change over time and comparing the PSA level to prostate size.

Researchers are also looking at whether new imaging tests, such as MRI scans, or other blood and urine tests, can be used to decide which men with an elevated PSA should have a biopsy.

Instead of a national screening programme, there is an informed choice programme called prostate cancer risk management for healthy men aged 50 or over who ask their GP about PSA testing. It aims to give men good information on the pros and cons of a PSA test.

If you're a man aged50 or over and decide to have your PSA levels tested after talking to your GP, theywill be able to arrange for it to be carried out for free on the NHS.

If results show you have araised level of PSA, your GP may suggest further tests.

Should I have a PSA test?

Because the results of the PSA test are not as reliable as doctors would like, other tests and investigations are needed to diagnose prostate cancer.

A PSA test cannot identify prostate cancer on its own, and changes in PSA levels alone are not a good reason to start treatment.

If you are thinking about asking for a PSA test, it is important that you first discuss whether it is right for youwith your GP so you understand what the results might mean.

The Prostate Cancer Risk Management Programme has information on the risks and benefits of the PSA test to help you decide whether or not to have it.

Want to know more?

• Should I have a PSA test?