Prostate cancer testing

How can I test for prostate cancer?#

The main test is a prostate-specific antigen (PSA) blood test. PSA is a protein made by cells in the prostate gland.

The prostate is a walnut-sized gland that sits below the bladder, in front of the rectum. It surrounds the urethra, the passage through which urine and semen leave the body. Some PSA produced by prostate cells passes into the bloodstream, and as men get older and the prostate grows larger, PSA levels may rise.

The PSA test measures the level of PSA in the blood and is used to detect an increased risk of prostate cancer. Higher than normal levels suggest there may be a problem with the prostate that needs further investigation.

What other factors can influence PSA levels?#

A raised PSA does not only happen with cancer. Other conditions, such as prostatitis (an infection or inflammation of the prostate), can also increase PSA. An elevated level simply means something is happening in the gland and that further checks may be needed.

Should I have a PSA test?#

Prostate cancer is one of the most common cancers in men. Each year many men are diagnosed with it, and some die from it. General guidance suggests that men over the age of 50, or over 40 with a family history of prostate cancer, should talk to their doctor about testing as part of their regular health checks.

Testing is also worth discussing if you have any symptoms that could point to a prostate problem, such as:

• needing to pass urine often, especially at night
• a poor or slow-to-start urine stream
• dribbling at the end of passing urine
• pelvic or back pain
• blood in the urine or semen (never ignore this)
• pain when passing urine or ejaculating

It is important to make an informed decision based on the current evidence about the benefits, the possible harms of testing, and any treatment that might follow.

What are the potential benefits of PSA testing?#

PSA testing can reduce a man’s risk of dying from prostate cancer. In a man with no symptoms, it can detect a potentially harmful cancer before it spreads, and early detection and treatment increase the chance of a cure. For some men, regular testing also provides reassurance.

Your doctor should explain your personal risk factors and the benefits and possible harms before you decide. Ask plenty of questions so you clearly understand what testing involves and what happens next, whether the result is normal or raised.

What are the possible harms of PSA testing?#

• False positive. Your PSA may be high even though you do not have cancer. The worry and the extra tests that follow (including a biopsy) can cause distress and physical side effects.
• False negative. PSA is not always raised in men who do have cancer, so a cancer can sometimes be missed.
• Over-diagnosis. PSA testing can find cancers that are not harmful and would never cause problems, because they grow very slowly or stay the same. Doctors cannot always be sure which cancers will remain harmless, so active surveillance or treatment may be recommended. Across all the men tested, this means some have monitoring or treatment they may not have needed.

What do the results mean?#

A PSA level that stays elevated suggests something is going on in the prostate, and further tests are needed to find out whether it is cancer or another condition.

• If your PSA level is over 3.0 ng/ml, the test should usually be repeated within 1 to 3 months, because PSA sometimes returns to normal on its own.
• Your doctor may also order a free-to-total PSA ratio test. If PSA stays elevated and the free-to-total ratio is low, you may be referred to a specialist (urologist) for more tests.
• If you have a family history of prostate cancer and/or are in your 40s, your doctor may recommend further testing if your PSA level is above 2.0 ng/ml.

An abnormal PSA result does not necessarily mean you have prostate cancer.

What are the next steps?#

Your doctor will weigh the results of your repeat PSA test alongside your age and family history before recommending what to do next.

• If the repeat results are not a cause for concern, talk to your doctor about future testing.
• If they still suggest a problem, you will be referred to a urologist for further investigation.

Further investigations can include:

• Digital rectal examination (DRE). The doctor inserts a gloved, lubricated finger into the rectum to feel the size and shape of the prostate. A normal DRE does not rule out prostate cancer.
• MRI scan. This assesses the size of the prostate and looks for abnormal areas. It helps the urologist decide whether a biopsy is needed and which part of the prostate to target.
• Biopsy. A needle is used to take several small tissue samples, which are examined in a laboratory to show whether the cells are malignant (cancerous) or benign. A biopsy is the only way to make a definitive diagnosis of prostate cancer. It can be done through the rectum or through the perineum, with appropriate anaesthetic.

If the biopsy is negative, you will usually be offered routine monitoring of your PSA. If later tests show a rise, you may need another biopsy or MRI. If cancer is found, a specialist such as a urologist or radiation oncologist will discuss treatment options with you.

Monitoring prostate cancer#

After a diagnosis, regular PSA blood tests are used to monitor the cancer. Prostate cancer usually causes PSA levels to rise as the tumour grows, so repeat tests can show whether the tumour is shrinking or enlarging and whether treatment is working.

Key points#

• The PSA blood test is the main test used to detect an increased risk of prostate cancer.
• Higher PSA levels do not always mean cancer; other conditions, such as prostatitis, can raise PSA too.
• Men over 50, or over 40 with a family history, should discuss testing with their doctor, as should anyone with urinary or related symptoms.
• PSA testing has benefits and harms, including false positives, false negatives and over-diagnosis, so make an informed decision.
• A biopsy is the only way to confirm a diagnosis, and regular PSA tests are used to monitor cancer after diagnosis.

Where to get help#