Prostate-Specific Antigen (PSA) Test
Definition
Prostate-specific antigen (PSA) is a protein made by the prostate gland. The prostate is a walnut-sized gland in men, located near the bladder and rectum. It produces a fluid that is part of semen. Most PSA is released into semen, but some is released into the bloodstream. If there is a problem with the prostate, the PSA found in the blood can become elevated.
Anatomy of the Prostate
Reasons for Test
The PSA test is used to:
- Screen for prostate cancer
- Monitor treatment for prostate cancer
- Help determine if cancer has returned in men who have already been treated for prostate cancer
An elevated PSA level may also be associated with prostatitis (inflammation of the prostate) and an enlarged prostate ( benign prostatic hypertrophy ).
What to Expect
Prior to Test
- Ejaculation can cause PSA levels to rise. Avoid sexual activity for 2-3 days before testing.
-
Some procedures can elevate PSA levels. Schedule your PSA test several weeks after any of these:
- Any prostate surgery (eg, TURP)
- Prostate biopsy
- Prostate massage
- Wait several weeks after successful treatment of prostate infections.
-
Some medications can lower PSA levels. Tell your doctor if you are taking:
- Finasteride (eg, Propecia, Proscar)
- Dutasteride (eg, Avodart)
Description of Test
You will roll up your sleeve. An elastic band will be wrapped around your upper arm. An area on your arm will be cleaned with alcohol. The needle will then be inserted into your arm. A small amount of blood will be drawn into a tube. The needle will be removed. Pressure will be applied to the puncture site. A small bandage may be placed on the site. Your blood will be sent to a lab for testing.
After Test
You will be able to leave after the test is done.
How Long Will It Take?
Drawing blood takes only a few minutes.
Will It Hurt?
It may be uncomfortable when the needle pierces your skin.
Results
The results are usually available in a few days to a week. Your doctor will talk to you about your results.
If your PSA level is slightly elevated but there are no other reasons to suspect prostate cancer, your doctor may recommend closely following your PSA levels. If your PSA level continues to rise or the doctor notices a lump during a digital rectal exam, he will probably schedule other tests, such as a prostate biopsy.
RESOURCES:
American Cancer Society
http://www.cancer.org/
American Urological Association Foundation
http://www.urologyhealth.org/
CANADIAN RESOURCES:
Canadian Cancer Society
http://www.cancer.ca/
Canadian Prostate Cancer Network
http://www.cpcn.org/
References:
Benson MC, Whang IS, Olsson CA, McMahon DJ, Cooner WH. The use of prostate specific antigen density to enhance the predictive value of intermediate levels of serum prostate specific antigen. J Urol . 1992;147:817-821.
Cancer facts: questions and answers about the prostate-specific antigen (PSA) test. National Cancer Institute website. Available at: http://www.cancer.gov/cancertopics/factsheet/Detection/PSA . Updated March 2009. Accessed October 25, 2007.
Fang J, Metter EJ, Landis P, Carter HB. PSA velocity for assessing prostate cancer risk in men with PSA levels between 2.0 and 4.0 ng/mL. Urology . 2002;59:889-893.
Prostate cancer. Mayo Clinic website. Available at: http://www.mayoclinic.com/health/prostate-cancer/DS00043 . Updated June 2009. Accessed July 22, 2009.
Stephan C, Stroebel G, Heinau M, et al. The ratio of prostate-specific antigen (PSA) to prostate volume (PSA density) as a parameter to improve the detection of prostate carcinoma in PSA values in the range of < 4 ng/mL. Cancer . 2005;104:993-1003.
Thompson IM, Ankerst DP, Chi C, et al. Operating characteristics of prostate-specific antigen in men with an initial PSA level of 3.0 ng/ml or lower. JAMA . 2005;294:66.
¹5/6/2009 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : Schröder FH, Hugosson J, Roobol MJ, et al. Screening and prostate-cancer mortality in a randomized European study. N Engl J Med. 2009;360:1320-1328.
Last reviewed October 2009 by Brian P. Randall, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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