Prostate-Specific Antigen (PSA)

What is PSA?

This blood test measures the level of prostate-specific antigen (PSA). PSA is a protein produced by the prostate gland and released in semen, with small amounts circulating in the blood. Both cancerous and noncancerous tissues in the prostate produce PSA. The latter can be bound to protein or circulate “freely” (unbound) in the blood. This test measures the total PSA (both bound and unbound) in the blood.

Prostate cancer is a common illness among men and a leading cause of death. Detecting abnormalities of this gland can save men’s lives. This type of cancer progresses slowly and without apparent symptoms. With an early diagnosis, one can receive a timely treatment and prevent any spread of malignancies.

Why take a PSA test?

This is an essential test for men who want to stay on top of their health. Getting tested regularly can help detect any abnormalities before they become more pronounced and end up inflicting a heavy burden on you and your life. For men who were already diagnosed with prostate cancer, the PSA test will be needed to follow up on whether their cancer is recurring and the make sure that the treatment path chosen was effective.

Men who have abnormal PSA levels need to check with their doctor and plan the next step. Those whose tests show abnormal levels of PSA will have to investigate further. To identify a cancer, you might need a digital rectal exam or a biopsy. A blood PSA test poses no risk and is included in men’s annual wellness checkup.

For use as a prostate cancer screening test, both the American Cancer Society (ACS) and the American Urological Association (AUA) recommend that men consider potential benefits and risks of testing when deciding.

The ACS recommendations include:

• Begin PSA screening at age 50 for average-risk men.
• Begin PSA screening at age 45 for high-risk men. This includes men who are African-American, or who have a first-degree relative (dad, brother, or son) who had prostate cancer before age 65.
• Begin PSA screening at age 40 for men with 2 or more first-degree relatives who had prostate cancer before age 65.
• Repeat screening annually or every 2 years based on the PSA result.

The AUA recommendations include:

• Begin screening at age 55 and continue through age 69 for average-risk men.
• Repeat screening every 2 years, or at different intervals based on PSA result.
• Consider screening men age 40-54 if they are high risk, including African-American men and men with a family history of prostate cancer.
• Consider continuing to screen men age 70 or older when they are in excellent health (defined by the AUA as men expected to live another 10-15 years).

What can cause PSA levels to rise?

PSA can be elevated due to many reasons including prostatitis, which is the inflammation (swelling) or infection of the prostate. Another reason can be having an enlarged prostate, which is also called benign prostatic hyperplasia (BPH). Finally, having prostate cancer can lead to high levels of PSA.

Some factors can show elevated PSA levels, stressing out the patient in vain. For example, when a man ejaculates two days before the test, his test will show what is called a ‘false positive’. So, make sure you talk to your physician about it.

What your PSA test results mean?

This test is used to evaluate prostate function, particularly as a screening test for prostate cancer. It is also used to help dietect prostatitis and benign prostatic hyperplasia (BPH).

Normal values of PSA are anything below 4 ng/mL. Values between 4-10 ng/mL are considered elevated and need to be investigated further. A PSA test should be well-analyzed before a doctor can make a diagnosis. The variations of this assessment include the following:

Percentage of free PSA – This test is used to indicate the presence of cancer. When PSA levels are high with a low percentage of free PSA, this has a high probably that a cancer has developed.

PSA with age – Your physician needs to take into account that PSA levels tend to elevate with age.

Where can I get a PSA test near me?

Please use our Lab Locator to find find a convenient testing location.

References

1. American Cancer Society. American Cancer Society recommendations for prostate cancer early detection. Available at: https://www.cancer.org/cancer/prostate-cancer/early-detection/acs-recommendations.html.
2. American Urological Association. Early Detection of Prostate Cancer (2018): AUA Guideline. Available at: https://www.auanet.org/guidelines/prostate-cancer-early-detection-guideline. Published 2013; Reviewed and Validity Confirmed 2018.

Reviewed By: Dr. Kurt Kloss, MD
Last Reviewed Date: May 24, 2019