Prostate-specific antigen (psa) test

The main screening test for prostate cancer is the prostate-specific antigen (PSA) test. It's a blood test that measures how much PSA is in your blood.

PSA is released into the blood from the prostate, which is part of the male reproductive system. A PSA test can show if you have normal or high amounts of PSA in your blood. A high PSA level can have many causes, including an enlarged prostate, an infection or, less often, prostate cancer.

The prostate-specific antigen (PSA) test is done to:

• Screen for prostate cancer. If your PSA level is higher than expected, your doctor may suggest other tests, including a prostate biopsy. This is because other common medical conditions, such as an enlarged prostate and prostatitis, can cause high PSA levels.
• Check if cancer may be present when results from other tests, such as a digital rectal exam, are not normal. A PSA test does not diagnose cancer, but it can be used along with other tests to determine if cancer is present.
• Watch prostate cancer during active surveillance or other treatment. If PSA levels increase, the cancer may be growing or spreading.
• Follow up after prostate cancer treatment to watch for any signs of the cancer coming back. A PSA level that rises after radical prostatectomy or radiation therapy for localized prostate cancer may mean the cancer has returned or has spread.

A health professional uses a needle to take a blood sample, usually from the arm.

Do not ejaculate during the 2 days before your PSA blood test, either during sex or masturbation. Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean.

Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.

Normal

Because normal PSA levels seem to increase with age, age-specific ranges may be used. But the use of age-specific ranges is controversial, and some doctors prefer to use one range for all ages. For this reason, it is important to discuss your test results with your doctor.

A PSA level within the normal ranges does not mean that prostate cancer is not present. Some men who have prostate cancer have normal PSA levels.

High values

High levels don't always mean that prostate cancer is present. PSA levels may be high if the prostate gland is enlarged (benign prostatic hyperplasia, or BPH) or inflamed (prostatitis).

If your PSA level is high, your doctor may refer you to a urologist. What tests come next will depend on your overall health, your chances of having prostate cancer, and your feelings about having tests and treatments. You may have a repeat PSA test, an MRI, or tests that look at your risk for prostate cancer. Or you may be scheduled for a prostate biopsy.