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PSA testing for prostate cancer

At the moment, there is no national screening programme for prostate cancer in the UK. Before we can screen for a disease, there must be an accurate test to use. Some trials have shown that using a test for prostate specific antigen protein (PSA) to screen for prostate cancer may reduce deaths or help some men to live longer. But other trials have shown no benefit. 

PSA levels in the blood may be raised in prostate cancer. But PSA can be raised for other reasons, such as infection or an enlarged prostate that is not cancer. So the PSA test is not reliable enough to use in a screening programme. 

Many early prostate cancers grow very slowly and may never cause any problems in a man's lifetime. So, if one is found through screening, it can lead to a man having unnecessary tests or treatments that can severely harm his quality of life. So, the disadvantages of screening outweigh the benefits.

If you want a PSA test

If you want to have a PSA test, you can ask your GP. They will talk you through the benefits and possible disadvantages. If you still want to have the test, your doctor will take a blood sample to test your PSA levels. They may also examine your prostate by putting a gloved finger into your back passage and feeling the prostate gland. They call this digital rectal examination or DRE.

Clinical trials are still looking into tests that we may be able to use for prostate screening in the future.

If you are at higher risk of prostate cancer

If you have close relatives with prostate cancer, have inherited a faulty gene, or are of black African or black Caribbean heritage you may be at a higher risk of prostate cancer. You may be able to have regular checks with a PSA test or rectal examination from the age of 40 to 45.

 

CR PDF Icon You can view and print the quick guides for all the pages in the About prostate cancer section.

 

 

The aim of cancer screening

Screening means looking for early signs of a particular disease in healthy people who don't have any symptoms. The aim of screening is to diagnose disease at an early stage before symptoms start. It is then easier to treat and more likely to be cured.

 

Why there is no national prostate cancer screening programme

To have a prostate cancer screening programme we would need a test that can reliably find cancers that would cause problems during a man's lifetime. There is a test called the PSA test that can help doctors work out how likely a man is to have prostate cancer. But this test is not specific enough to use as part of a national screening programme. And there isn't enough evidence that the benefits of testing outweigh the harms. 

Research studies into using the PSA test for prostate cancer screening have had conflicting results.  So we don't know whether a screening programme would help to reduce deaths from prostate cancer. 

Unlike many other cancers, prostate cancers can grow very slowly and may be there for years before they are found. This type of cancer may not cause any symptoms or problems at all during a man's lifetime. By the age of 80, many men will have some cancer cells in their prostate, but only 1 in 25 of them will actually die from prostate cancer. 

On the other hand, some prostate cancers are faster growing and can spread to other parts of the body within a few years. For screening to be most helpful, it would only pick up prostate cancer that is faster growing and likely to be a threat to a man's health. But there is currently no test that can reliably do this. 

 

The PSA test

PSA stands for prostate specific antigen. It is a protein produced by prostate cells and can be measured with a blood test. 

PSA levels can be raised if a man has prostate cancer. But the levels can also be raised when a man has other medical conditions, such as an enlarged prostate that is not cancer called benign prostatic hypertrophy or BPH. 

PSA can also be raised by prostate infection (prostatitis), exercise and sex. Some drugs used to treat a benign enlarged prostate can lower PSA. 

Another problem is that all men have slightly different PSA levels. So it is hard to say what is normal, and what is high. This means that not all men with high PSA have prostate cancer. And not all men with prostate cancer have high PSA.

  • A PSA level of 4 or lower is usually considered normal but some men with this reading will have prostate cancer
  • A PSA between 4 and about 10 is usually caused by an enlarged prostate, not cancer. But some men with this reading will have prostate cancer
  • A PSA level above 10 is a sign that cancer is more likely to be present. But it can also be caused by an enlarged prostate that is not cancer

Generally speaking, the higher the PSA level, the more likely it is that there is a cancer in the prostate. But in early prostate cancer, PSA levels are usually relatively low. It is not possible to pick out a particular PSA reading and say “people above this level have cancer and those below don't”. PSA also naturally tends to go up as men get older.

 

Possible benefits of the PSA test

If you have a normal result the test could reassure you that you are unlikely to have prostate cancer.

The PSA test can help to find some prostate cancers early before any symptoms develop.

Treating prostate cancer in the early stages may help you to live longer but the evidence for this is not clear.

Finding prostate cancer early may help to avoid the problems of a more advanced cancer, such as symptoms due to cancer spread.

 

Possible drawbacks of the PSA test

The PSA test can't really tell us clearly whether a man has prostate cancer. It misses some cancers. So some men with a normal reading will have cancer but will be falsely reassured that they don't.

Up to 2 out of 3 men with raised PSA levels don't have cancer and will have unnecessary worry.

Men with a high PSA reading may need further tests such as a prostate biopsy. These tests can be uncomfortable and many men find them embarrassing. They also have risks. Some men who have a needle biopsy will have infection or ongoing bleeding afterwards.

The test can pick up very early, slow growing cancers that would never cause any problems or symptoms in a man's lifetime. This is called overdiagnosis.

We can't always tell which cancers will grow quickly and which will grow slowly. Men who have a cancer that would not have caused them a problem will have treatment they don't need. This is called overtreatment. Treatment can cause side effects, such as difficulty getting an erection (impotence) and leaking of urine (incontinence). These side effects can greatly affect your quality of life.

 

If you want a PSA test

Although there is no prostate screening programme, men aged over 50 can ask their GP for a PSA test. This is part of the UK Prostate Cancer Risk Management programme. 

If you ask to have the test your GP first explains all the possible benefits and risks. They will give you a leaflet to read and they or the practice nurse can answer any questions that  you have.

If you still want to have the test after considering the information, your GP or practice nurse will take a blood sample. 

When you have the test you should not have

  • A urine infection
  • Ejaculated for 48 hours beforehand
  • Exercised heavily in the previous 48 hours
  • Had a prostate biopsy within the last 6 weeks

These things may raise your PSA level.

Your GP may also examine your prostate. They do this by gently putting a gloved finger into your back passage (bottom) and feeling your prostate gland. They call this digital rectal examination, or DRE.

 

After a PSA test

You usually get your PSA test result within a couple of weeks. 

If you have a normal PSA level, experts currently think that you don't need another test for at least 2 years.

If your PSA level is slightly raised, you should have a repeat test 1 to 3 months later to see if the PSA level is going up or is stable. There are guidelines for GPs about what to do in these circumstances.

If you have a raised PSA, your doctor will refer you to a specialist for further tests. These tests include an examination of your prostate gland and possibly a prostate biopsy. We have detailed information about prostate cancer tests

 

PSA testing for men at higher risk of prostate cancer

Some men may start having regular PSA tests if they have an increased risk of prostate cancer.

If you have family members with prostate cancer

There is some evidence to show that prostate cancer can run in families. This means that if you have a relative diagnosed with prostate cancer, your risk is higher than in the general population. Your risk is higher if

  • Your brother was diagnosed
  • The relative was younger than 60 when they were diagnosed
  • You have several relatives diagnosed with prostate cancer

Currently doctors don’t know the best way to monitor people who are at high risk. But if you have a family history of prostate cancer, you may want to discuss screening with your GP. They will look at your family history and the ages of your relatives when they were diagnosed. 

If you have a strong family history of prostate cancer your GP may suggest that you have regular PSA tests and examinations of the prostate gland. They may refer you to a genetics clinic if they think that may be helpful. Generally, doctors suggest screening from around the age of 40 to 45 if you have a strong family history that raises your risk of cancer.

If you are black-African or black-Caribbean

Men of black-African or black-Caribbean heritage have an increased risk of prostate cancer. You can talk to your GP about the possible risks and benefits of having a PSA test.

 

Research into prostate cancer screening

A lot of research has been carried out into prostate cancer screening in recent years. A review of 6 large prostate cancer screening trials reported in 2010. It found that screening increased the number of men diagnosed with early stage prostate cancer. But screening didn't reduce deaths from prostate cancer or help men to live longer. A 20 year Swedish study reported in 2011. It also found that prostate cancer screening in the general population has very limited benefit. 

The European Randomised Study of Screening for Prostate Cancer (ERSPC) was set up in 1991 and is still going on. For this study, 182,000 European men aged 50 to 74 were divided into 2 groups. One group was offered PSA screening every 4 years. The other group did not have screening. The latest findings were published in 2014. 

The study found that fewer men died from prostate cancer when they had screening. But many doctors and researchers feel that it still doesn't tell us whether this outweighs the side effects of treatment, such as impotence and incontinence. The researchers said that to prevent one death from prostate cancer over the 11 years, 1,055 men had to be invited for screening, with 37 cancers being found.

A similar study in the US is called the Prostate, Lung, Colorectal and Ovarian (PLCO) cancer screening trial. For prostate cancer it involved 76,000 men aged 55 to 74. Half of the men in the study were offered a yearly PSA test for 6 years. After 10 years the researchers found that more men in the screening group were diagnosed with prostate cancer than in the other group. But the number of men in each group who died was very similar.

So we don't know yet whether it is helpful to regularly screen men for prostate cancer. Researchers are trying to find tests that are better than the PSA test in the hope that this will make screening more worthwhile. 

You can read about these tests on the research into diagnosing prostate cancer page.

Research into screening for men at higher risk

A UK trial called IMPACT aims to find out how best to monitor men who are at higher than normal risk of prostate cancer. It is giving yearly PSA testing to men who have inherited a gene change that increases their risk of prostate cancer. 

Early results of the IMPACT trial were released in September 2010 for the first 300 men. The results show that regular PSA screening may be helpful for men at higher risk of prostate cancer. It found that men with particular gene faults who developed prostate cancer tended to have faster growing cancers than men without the faulty genes. 

These are early results and it will be some time before we know the final results of this trial. The researchers need to monitor the men for at least 5 years. 

You can find out more about the IMPACT trial.

You can also find out about trials into prostate cancer screening on our clinical trials database.

 

Related information

We have information about clinical trials for prostate cancer on our clinical trials database.

You can find further information and resources such as DVDs on the NHS prostate cancer risk management website.

Even if you have had a normal PSA test it is still important to be aware of any changes in your body that could be due to prostate cancer. You can look at our information about the symptoms of prostate cancer

See your doctor if you have any changes. They can arrange for tests if necessary.

Prostate impact statement PSA

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Updated: 3 December 2014