Prostate-Specific Antigen (or PSA) is a protein produced mostly, but not exclusively, by the cells of the prostate gland. The PSA test measures the level of PSA in the blood. When the prostate gland enlarges, PSA levels in the blood tend to rise.

PSA levels can rise due to cancer or benign (not cancerous) conditions. Because PSA is produced by the body and can be used to detect disease, it is sometimes called a biological marker or tumor marker. Even after prostate removal, small amounts of PSA may be measurable since PSA is produced in small amounts by most tissues, especially the salivary and parotid glands, and breasts.

Why is the PSA Test Done?

The PSA test is used with a digital rectal exam (DRE) to help your doctor detect prostate cancer in men age 50 and older. During and after treatment, PSA can be used to monitor prostate cancer.

How Are PSA Results Reported?

• PSA test results report the level of PSA detected in the blood. The PSA level that is considered normal for an average man ranges from zero to 4 nanograms per milliliter (ng/ml).
• A PSA level of 4 -10 ng/ml is considered slightly elevated; levels between 10 and 20 ng/ml are considered moderately elevated; and anything above that is considered highly elevated.

The higher your PSA level, the more likely it is that cancer is present. But because various factors can cause PSA levels to fluctuate, one abnormal PSA test does not necessarily indicate a need for other diagnostic tests.

What if the Results Show an Elevated PSA?

Discuss your PSA test results with your doctor. There are many reasons for an elevated PSA level, including

• Prostate cancer
• Benign prostate enlargement
• Inflammation or infection
• Age

If there are no other indicators that suggest cancer, your doctor may recommend repeating DRE and PSA tests regularly to monitor any changes.