PSA (Prostate-Specific Antigen) Test

What is PSA (prostate specific antigen)?

Prostate specific antigen (PSA) is an enzyme produced only by the prostate gland. The prostate gland is a doughnut-shaped gland located in a man's pelvis in the small space between the base of the penis and the bladder. The prostate makes the fluid that nourishes sperm and carries sperm during ejaculation. The amount of PSA produced by the prostate gland can be helpful in detecting prostate cancer very early.

Why is PSA screening important?

The amount of PSA produced by the prostate usually increases if you have prostate cancer. Checking for high PSA levels helps health care providers diagnose prostate cancer early. It also is a way to check how well treatment of prostate cancer is working.

Prostate cancer has become the most commonly diagnosed cancer among men in the US. It is the second leading cause of cancer deaths of men in the US. The prostate cancer death rate is especially high among African American men. The risk of prostate cancer increases with age.

PSA can be measured with a simple blood test. It is an important test because prostate cancer often has no symptoms in its early stages.

How is the test used?

PSA circulates in a man's blood. Normal levels, which increase with age, have been determined. The PSA blood serum test shows whether the amount of PSA in your blood is in the normal range.

Not all health care providers agree about the value of the PSA blood test and whether it should be done routinely for men over a certain age. However, the American Cancer Society suggests that health care providers should offer a yearly PSA blood test and rectal exam to men age 50 or older.

If you are at increased risk for prostate cancer (for example, if you are African American or have a family history of prostate cancer), your health care provider may recommend starting screening earlier than age 50.

What are the advantages of PSA screening?

The advantages of the PSA test are:

• It can be done with a simple blood test.
• It is less expensive than other tests, such as ultrasound scans.
• It helps detect small cancers that can't be found with a physical exam.
• If you have prostate cancer, it can be used to help see how well your treatment is working.
• It can be used to look for the return of prostate cancer after treatment.

What are the disadvantages of PSA screening?

The disadvantages of the PSA test are:

• It does not always detect prostate cancer. The results of the test are in the normal range in 25% to 45% of men with prostate cancer.
• Other prostate conditions, namely prostate infection and prostate enlargement (benign prostatic hyperplasia), can increase the PSA level.

Because of these limitations to PSA screening, you should discuss having the test with your health care provider.

For more information, you can also call the American Foundation for Urologic Disease at (800) 242-2383 or visit their Web site at http://www.urologyhealth.org/.

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