Finger prick sample collection for prostate-specific antigen test

How Is Prostate-Specific Antigen Test Done?

Medically reviewed on June 27, 2022 by Jordan Stachel, M.S., RDN, CPT. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

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The human prostate is a special organ that is only present in men, but like other organs, the prostate can succumb to plenty of problems. An enlarged prostate, medically referred to as “benign prostatic hyperplasia,” is one of the most common prostate conditions. It affects about 50 percent of men aged 51 to 60 and about 90 percent of men aged 80 and up [1].

Benign prostatic hyperplasia is mostly harmless, but prostate cancer is a different story. Behind lung cancer, prostate cancer mortality is the second leading cause of cancer-related deaths in men in the United States. It is the most common cancer in men, not including forms of skin cancer, and estimates suggest that about one in eight men will receive a prostate cancer diagnosis at some point in his life [2].

The good news is that prostate cancer can be treated, but the effectiveness hinges on how early the cancer is found, so testing and screening procedures are especially important. One simple blood test for prostate cancer is the prostate-specific antigen test. Other measures can promote a healthy prostate, like learning how to improve prostate health and checking prostate health.

Learn more about the PSA, or prostate-specific antigen test, and how it is performed below.

Understanding the Prostate Gland

As mentioned, only men have a prostate, which is a small gland shaped like a walnut. This gland is in front of the rectum and below the bladder. The prostate gland’s main function is to produce some of the fluid that makes up semen, which is the substance that nourishes and transports sperm cells. The seminal fluids are produced by the seminal vesicles, which are located just behind the prostate gland. Passing through the center of the prostate gland is the urethra, a tube that transports semen and urine out of the body via the penis [3].

The prostate gland stays small on average, but it can potentially change size. It’s not uncommon for the prostate to grow as you get older [3]. Consider a regular screening test to detect and treat any related problems such as prostate cancer.

A Look at Prostate Cancer

Prostate cancer refers to any cancer originating within the prostate. Most all forms of prostate cancer are adenocarcinomas, which are cancers affecting the gland cells. In the prostate, the gland cells are what create the fluids that are included in the semen. In rarer cases, you may have other types of cancer in the prostate, like small cell carcinomas or sarcomas [3].

Although some prostate cancers can grow quickly and aggressively spread to neighboring tissues, most cases of prostate cancer involve slow growth that is confined to the gland [4]. In fact, some men may not even know they have prostate cancer until they have been tested or examined for other health problems.

Part of that comes from the symptoms of prostate cancer or lack thereof. In its early stages, prostate cancer typically presents no symptoms, or the symptoms may be so minimal that you don’t even notice [4]. More advanced forms of prostate cancer may cause:

  • Reduced pressure when urinating
  • General urination problems
  • Blood in the semen and/or urine
  • Erectile dysfunction
  • Unintended weight loss
  • Bone pain [4]

What Is Prostate-Specific Antigen Testing?

One of the most common forms of screening is the prostate-specific antigen test. Prostate-specific antigen is a protein produced in cells within the prostate. It is primarily found in semen, but some minor amounts are found in the blood. Normal and cancerous cells produce PSA, so increased PSA levels may indicate an increased chance of prostate cancer [5].

Prostate-specific antigen is measured in nanograms per milliliter of blood. However, no set cutoff point indicates whether there is prostate cancer. Most healthcare providers use 4 ng/mL as the cutoff level, meaning that if your PSA levels are 4 ng/mL or higher, there may be prostate cancer. Most men who do not have prostate cancer have a PSA level below 4 ng/mL, but some healthcare providers will recommend a cutoff as low as 2.5 or 3 ng/mL [5].

Men with a PSA level between 4 and 10 ng/mL are considered “borderline,” meaning they have about a one in four chance of developing prostate cancer. A PSA level higher than 10 ng/mL has a prostate cancer chance of over 50 percent. However, some people with prostate cancer have PSA levels well below 4 ng/mL [5].

Factors That Increase Prostate-Specific Antigen

Part of what makes setting a “cutoff” so difficult is that PSA levels are prone to fluctuation based on various factors not related to cancer. Most of these factors are benign and mostly harmless. Factors that can increase PSA levels include:

  • Old age
  • Benign prostatic hyperplasia (an enlarged prostate)
  • Prostatitis (inflammation of the prostate gland)
  • Some medicines, particularly those that raise testosterone levels
  • Some urologic procedures

Ejaculation can also increase PSA levels in the short term, so your healthcare provider may recommend not having sex for a few days before a PSA screening. Riding a bike may also cause elevated PSA levels, though more studies are necessary [5].

Factors That Reduce Prostate-Specific Antigen

Some factors can also reduce PSA levels, including:

  • 5-alpha reductase inhibitors (often used for treating benign prostatic hyperplasia)
  • Some herbal mixtures and dietary supplements
  • Long-term use of aspirin, statins, thiazide diuretics, and other medications [5]

Abnormal Prostate-Specific Antigen Levels

Suppose the PSA test result shows abnormal or elevated PSA levels. In that case, your healthcare provider will likely recommend further testing and evaluation to determine if there is prostate cancer or other prostate problems. Remember, a high PSA level does not necessarily mean there is cancer. Your healthcare provider will likely advise:

  • Getting a second PSA test at a later date
  • Getting another type of test to determine if there is cancer
  • Getting a prostate biopsy

Remember, it's better to go through multiple screening tests to detect any possible cancer cells to receive early prostate cancer treatment if needed.

Who Should Get a Prostate-Specific Antigen Test?

For a time, healthcare providers recommended annual PSA testing for men aged 50 and older, but some organizations have cautioned against routine population screening. This also comes from the potential for both false-positive and false-negative PSA results. If you think you have an increased risk of prostate cancer, consult your healthcare provider to determine if a prostate-specific antigen test would be beneficial for you [6].

Most often, a PSA test is combined with a digital rectal exam (DRE). During a DRE procedure, a healthcare provider wears a glove and inserts a finger into the rectum. Through the rectum, a healthcare provider can potentially feel any bumps or hard spots on the prostate, which can indicate cancer. This may be uncomfortable, but it’s a short, simple procedure. It’s less effective on its own, but it can be helpful when a prostate-specific antigen test comes back with normal PSA levels [5].

Beyond a PSA test or DRE, a healthcare provider may perform a prostate biopsy if they suspect that there is cancer. This involves taking a sample of prostate tissue, which can then be tested and examined to determine the presence of cancerous cells [5].

A prostate-specific antigen is an increasingly helpful tool in determining your prostate health and providing one step in the diagnosis. Consult your healthcare provider if you think you might benefit from a PSA test.

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References

1. Prostate Enlargement (Benign Prostatic Hyperplasia). NIH. URL. Accessed June 27, 2022.

2. Key Statistics for Prostate Cancer. American Cancer Society. URL. Accessed June 27, 2022.

3. What Is Prostate Cancer? American Cancer Society. URL. Accessed June 27, 2022.

4. Prostate cancer. Mayo Clinic. URL. Accessed June 27, 2022.

5. Screening Tests for Prostate Cancer. American Cancer Society. URL. Accessed June 27, 2022.

6. Prostate-Specific Antigen (PSA) Test. American Cancer Society. URL. Accessed June 27, 2022.

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