PSA stands for Prostate Specific Antigen and it’s a compound created by the prostate and naturally occurring in the male.
However, If the prostate is infected or diseased, it can generate larger than normal quantities of PSA. For example, while the usual level in a particular man might be 4, a urinary infection can make it shoot up to 20 or higher. The doctor may run the test some time later as a means of knowing that the prostate has returned to the usual value after the infection.

A raised level can also be indicative of cancer in the prostate, and it used to be standard practice for men to be offered a regular PSA test. But the approach now is more cautious, as a higher level may not actually be caused by cancer, so that intrusive procedures, including scans and a biopsy may be done pointlessly. This “false positive” result is a concern as biopsies are not without risk. The flip side is that cancer may start developing without raising the PSA, so that a low PSA can give assurance that is not valid, a “false negative”.

What’s a normal level of PSA?

Macmillan Cancer Support says:
“Unlike some other blood tests, there is not one normal PSA level for everyone. The PSA level naturally gets higher as you get older and varies depending on the size of your prostate. The size of the prostate is different for each man and the prostate gets bigger with age.
Your doctor will tell you what they think the normal level of PSA should be for you. They generally use these levels:
• For men in their 50s, a PSA level of up to 3 nanograms per millilitre of blood (3ng/ml).
• For men in their 60s, a PSA level of up to 4 ng/ml.
• For men in their 70s, a PSA level of up to 5 ng/ml.
• There are no PSA level limits for men aged 80 and over.”

So is a regular test a good idea?

The US Centers for Disease Control and Prevention says:
“Men who are 55 to 69 years old should make individual decisions about being screened for prostate cancer with a prostate specific antigen (PSA) test.
Before making a decision, men should talk to their doctor about the benefits and harms of screening for prostate cancer, including the benefits and harms of other tests and treatment.”
They add that “Older men are more likely to have false positive test results.” and that “Men who are 70 years old and older should not be screened for prostate cancer routinely.”

The National Health Service says that:
“A raised PSA level in your blood may be a sign of prostate cancer, but it can also be a sign of another condition that’s not cancer, such as: an enlarged prostate, prostatitis, urinary infection.
There’s currently no screening programme for prostate cancer in the UK. This is because it has not been proved that the benefits would outweigh the risks. More research is needed to determine whether the possible benefits of a screening programme would outweigh the harms of:
• overdiagnosis – people being diagnosed with a cancer that would never cause symptoms or shorten life expectancy
• overtreatment – people being treated unnecessarily for tumours that would unlikely be harmful”

Link to my post on “Prostate Cancer