PSA test for prostate cancer
Prostate-specific antigen, or PSA, blood test is used to help diagnose prostate cancer.
However, an increased PSA level can also indicate an enlarged prostate, prostatitis or a urinary infection.
If PSA levels are raised, a biopsy tissue sample may be taken from the prostate for laboratory testing to check for cancer.
There is no routine NHS screening programme for prostate cancer because misleading test results could result in unnecessary distress and treatment.
PSA levels are measured in nanograms per millilitre of blood (ng/ml). Whether a PSA level is “normal” depends on the individual and their age. Cancer Research UK uses the following rough guide:
- 3 ng/ml or lower is considered in the normal range for a man under 60 years old
- 4 ng/ml or lower is normal for a man between 60 to 69 years old
- 5 ng/ml or lower is normal for a man 70 years old and over
A reading higher than 5ng/ml but lower than 10 ng/ml is usually due to a benign enlarged prostate, Cancer Research UK says. A reading above 10 ng/ml may also indicate benign prostate disease. However the higher the PSA level, the more likely it is to be prostate cancer.
Just as significant as the PSA level is the trend in that number (whether it is going up, how quickly and over what period of time). It is also important to understand that the PSA test is not infallible. Most men with elevated PSA levels have non- cancerous prostate enlargement, which is a normal part of ageing. Conversely low levels of PSA in the bloodstream do not rule out the possibility of prostate cancer..
How is the PSA test done?
The test involves drawing blood, usually from the arm. The sample is sent to a laboratory for analysis.