Prostate Specific Antigen (PSA)

What is Prostate Specific Antigen (PSA)?

PSA or prostate specific antigen is a protein produced only by prostate gland cells. Its purpose is to improve sperm mobility. Normal men have low levels of PSA in the blood. The PSA level usually increases with age as the prostate enlarges.

Is PSA a cancer test?

PSA is not a specific test for cancer. It is a marker of cancer risk. To confirm if cancer is present, it is necessary to take a biopsy of the prostate. The biopsy will also help to determine how aggressive a cancer is.

How is the test used?

PSA is used in two ways: to identify men at risk for prostate cancer before they develop symptoms (screening), and to monitor men with prostate cancer.

A single test should not be used as the only indicator of cancer risk. If it is high, it is usually repeated a few months later.