Prostate-specific antigen – A simple blood test

Prostate-specific antigen, or PSA, is a protein that the prostate gland produces. A PSA test is a simple test that measures the amount of prostate-specific antigen a man has in his blood.

When the prostate gland is healthy, usually very little PSA escapes through the wall of the gland into the blood.

Before the test

Ejaculation can make a man’s PSA temporarily rise, so the doctor may tell you and your loved one not have sex several days before the test.

Be sure to tell the doctor about any medicines or herbal remedies that your loved one is taking, as these can also affect his score.

Other factors that can affect PSA levels include:

  • Infection
  • Inflammation
  • Benign prostatic hyperplasia (BPH) and BPH medicines

The doctor will withdraw a blood sample with a needle and send it to a laboratory for analysis.

What’s normal?

It used to be that a PSA level above 4 ng/mL (which means 4 nanograms per milliliter) was generally considered to be above normal.

Now, some doctors believe that the “normal” cutoff should be lower, as some men with lower numbers can still have prostate cancer.

And men with high levels of prostate-specific antigen may have conditions other than prostate cancer, such as benign prostatic hyperplasia (BPH) and prostatitis.

When should men be screened?

The American Urological Association (AUA) does not recommend screening men who are less than 40 years old.

AUA also does not recommend routine screening of men who are ages 40 to 54 at average risk of developing prostate cancer.

For men who are 55 to 69 years of age, AUA recommends that men discuss the pros and cons of PSA screening with their healthcare professionals.

The American Cancer Society, however, suggests that all men with average risk discuss having a baseline PSA test and digital rectal exam at age 50.

Why the difference?

This has been an evolving issue and is part of a larger debate within the medical community about whether men are being “over-treated” for prostate cancer.

In the end, the decision is up to you and your loved one! But understand that if your man wants to be tested, he may need to push for it.

Be proactive

When your loved one goes for his yearly annual exam, he should talk to his doctor about whether prostate-specific antigen testing and a digital rectal exam (DRE) are right for him.

If the doctor orders a PSA test, always ask for the test results. Never assume that “no news is good news.”

Understand that having a low PSA score does not always mean that a man does not have prostate cancer, just as having a high number does not always mean that he does have prostate cancer.

These tests are not 100% accurate and results may even vary from one lab to another.

Testing after treatment

PSA tests after treatment for prostate cancer may be stressful. You may have fears that the cancer has returned.

Take heart in knowing that if this happens, there may be other treatment options to consider.

Next: The prostate exam

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What are the causes?
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American Urological Association. Early detection of prostate cancer: AUA guideline.  Accessed March 20, 2015.

The American Cancer Society. Prostate Cancer. Accessed March 15, 2015.

Walsh PC. Guide to Surviving Prostate Cancer. New York, NY: Time Warner Book Group; 2001.

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