More about prostate cancer testing

Research has not yet clearly shown if the benefits of testing for prostate cancer outweigh the harms. The issue can be confusing especially for men with an average risk of developing prostate cancer. There are often conflicting messages from health and advocacy groups and different practices among doctors. Here is some more detailed information to help you make an informed decision with your doctor.

Early testing can help detect prostate cancer

The PSA (prostate specific antigen) test was first developed to monitor the progression of prostate cancer and to watch the tumour’s response to treatment.

When combined with a digital rectal exam (DRE), the PSA test can also be an effective test to help find (diagnose) cancer in men who have symptoms of prostate cancer. If prostate cancer is suspected, further test (TRUS and biopsy) are needed to confirm the diagnosis.

Limits of prostate cancer testing

The PSA and DRE tests have a high rate of false-positive results. A false positive means that the test result suggests cancer, even though there is no cancer. In other words, it’s like a false alarm. A false positive result can lead to unnecessary and invasive follow-up testing. Research shows that up to 20% of men may experience side effects such as blood in the urine, pain and temporary impotence from a trans-rectal needle biopsy.

PSA and DRE tests can also give false-negative results. This means no cancer is detected, even though cancer is present. Getting a false-negative result can cause you or your doctor to ignore symptoms of prostate cancer. The U.S. Preventive Services Task Force estimated in 2002 that 10–20% of early prostate cancers are missed by PSA testing.

The PSA test may detect prostate cancer that will not grow or spread during a man's lifetime. In these cases, doctors may suggest “active surveillance” (often called watchful waiting) of the prostate cancer. For active surveillance, the doctor monitors the cancer regularly rather than immediately starting treatment with surgery, radiation or medication.

Deciding what to do in this situation can be a difficult decision. It is useful to know that unlike many other cancers, some men have prostate cancer for years without it affecting their health. Recent research has shown that up to 50% of cancers that are detected by the PSA test may never need to be treated. Detection of these types of prostate cancer tumours is called “overdiagnosis”. An overdiagnosis can increase stress and anxiety. Some men may also have unnecessary treatments that expose them to more serious risks. For example, a radical prostatectomy (removal of the entire prostate) and external beam radiation can cause sexual dysfunction and/or urinary problems. Hormone drug treatment can lead to sexual dysfunction, breast swelling and hot flashes.

Can prostate cancer testing save lives?

For men who do not have symptoms of prostate cancer, the research findings are not clear. No screening test is 100% accurate. A good screening test results in decreased death rates in people with cancer. However, researchers also look for other benefits of screening including improved quality of life and less harmful treatments.

Two large studies published in 2009 compared men who have regular PSA screening versus men who do not have regular PSA screening. One study from Europe (ERSPC) found that routine PSA testing reduced prostate cancer death by 20%. However, a study from the US (PLCO) did not find any decrease in prostate cancer deaths with routine PSA testing. Although death rates from prostate cancer have decreased over the years, research suggests that this is likely due to changes in how prostate cancer is diagnosed and treated. More research is needed to determine if PSA testing saves lives or not.

Find out more about research into prostate screening.

Last modified on: 08 November 2010