A blood test that measures the amount of prostate-specific antigen (PSA) in the blood.
PSA is a protein produced by the prostate, a male sex gland that generates some of the seminal fluid found in ejaculate. An elevated PSA level may be an indication of prostate cancer.
PARTS OF THE BODY INVOLVED
Arm (for the removal of blood)
REASONS FOR PROCEDURE
PSA levels become elevated in men with prostate cancer.
A PSA test may be done for several reasons:
- To screen for prostate cancer in men age 50 and older, or in younger men who are at increased risk for the disease.
- To check the effectiveness of anti-hormonal therapies (LHRH agonists or anti-testosterone agents) in men who are being treated for prostate cancer.
- To determine if cancer has returned in men who have already been treated for prostate cancer. This is when the PSA test is most accurate.
RISK FACTORS FOR COMPLICATIONS DURING THE PROCEDURE
Collecting blood from a vein carries minimal risk. Some people may develop a bruise or a small collection of blood under the skin at the site of the needle stick. This is called a hematoma. The chances of developing a hematoma are greater for people taking aspirin or other blood-thinning medications (e.g., Coumadin).
WHAT TO EXPECT
Prior to Procedure
- Ejaculation can cause levels of PSA to rise, so avoid sexual activity for two to three days before testing.
- Cystoscopy, needle biopsy, and rectal exam of the prostate can elevate PSA levels. Schedule your PSA test for several weeks after any of these exams.
- Wait several weeks after successful treatment of a urinary tract infection or prostatitis (inflammation of the prostate) to have your PSA level tested.
During Procedure
A blood sample is taken from a vein in your arm.
Anesthesia
None.
After Procedure
- Resume your normal sexual activity.
- If a hematoma develops, place a piece of cotton over the affected area under a well-secured band-aid. Make sure the pressure is firm.
Description of the Procedure
You will roll up your sleeve and the person drawing blood will wrap an elastic band, or tourniquet, around your upper arm. He or she will clean your arm near the inside of your elbow with alcohol, and then insert a needle into your vein. A small amount of blood will be drawn into a collection tube. Pressure will be applied to the puncture site with a gauze pad or cotton ball as the needle is removed, and for several moments after. A small bandage may be placed on the puncture site. Your blood will then be sent to a laboratory for testing.
How Long Will It Take
Drawing blood takes only a few minutes. Laboratory results are usually available within a few days or a week.
Will It Hurt
It may hurt slightly as the needle pierces your arm.
Possible Complications
- A small bruise or hematoma where the needle was inserted into your arm.
- Lightheadedness. If this occurs, drink some juice or eat a snack.
- Rarely, lightheaded patients may faint.
Average Hospital Stay
None. A PSA test is done in your doctor’s office, a clinic, or a hospital laboratory.
Postoperative Care
None.
OUTCOME
PSA test results are reported as nanograms of PSA per milliliter of blood (ng/mL).
This table shows the current classification of PSA levels. (These values may change in the coming years as more information is gained regarding the differences in “normal” PSA levels for men based on their age, family history, and race.)
Normal
0 to 4 ng/mL
Slightly elevated
4 to 10 ng/mL
Moderately elevated
10 to 20 ng/mL
Highly elevated
20 ng/mL or higher
The recommendations for follow-up after a normal PSA test result vary. You may be advised to be retested in one year, or you may be told that it is unnecessary for you to be retested for several years. It is important to note that about one-fifth of men with early prostate cancer receive normal PSA test results.
If the test reveals that your PSA level is elevated, your doctor may repeat the test. Your doctor should also do a digital rectal exam to manually check for any physical abnormalities of the prostate. PSA levels rise with age, and can also increase in response to many noncancerous conditions including benign prostate enlargement, inflammation, and infection. Only about one-third of men with an elevated PSA level have cancer. If there are no other indications of cancer, your doctor may recommend repeating the PSA test regularly to monitor changes.
If your PSA level has increased and/or the doctor notices a lump during a digital rectal exam, he or she will probably schedule diagnostic tests such as a urine test, imaging tests, x-ray, or cystoscopy to determine the problem.
If your doctor suspects prostate cancer, a biopsy will be recommended. This is the removal of a sample of prostate tissue for testing. It is done as an outpatient procedure.
CALL YOUR DOCTOR IF ANY OF THE FOLLOWING OCCURS
- Blood continues to seep out of the puncture site.
- The puncture site becomes red, swollen, or painful.
- Your doctor’s office does not call you with your test results within one or two weeks.
SOURCES:
Cancer facts: Questions and answers about the prostate-specific antigen (PSA) test. National Cancer Institute. Available at:http://cis.nci.nih.gov/fact/5_29.htm. Accessed November 25, 2002.
Prostate cancer screening: know your options. Mayo Clinic. Available at: http://www.mayoclinic.com. Accessed November 26, 2002.
