What is 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.afud.org.


Disclaimer: This content is reviewed periodically and is subject to
change as new health information becomes available. The
information provided is intended to be informative and educational and is not a
replacement for professional medical evaluation, advice, diagnosis or
treatment by a healthcare professional.
HIA File CNC3538F.HTM Release 9.0/2006. Copyright © 2006 McKesson Corporation and/or one of its subdiaries. All Rights Reserved.
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