Prostate-Specific Antigen (PSA) Test: What Is PSA?

PSA is a protein (called prostate specific antigen) produced by cells that line the small glands inside the prostate. When a man has prostate cancer, his PSA levels tend to increase, which is why a PSA test is often used by physicians to screen for prostate cancer.

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What is a PSA test?

To conduct a PSA test, a physician will take a blood sample and send it to a laboratory for analysis. A PSA test result is an important factor when determining prostate cancer diagnosis, plan and treatment. However, an elevated PSA does not always mean a man has prostate cancer. Additionally, a low PSA does not mean that cancer is not present.

Why are PSA tests done?

PSA tests measure the level of prostate-specific antigen in your blood. This protein, produced by the prostate gland, can be elevated due to prostate cancer, benign enlargement, or inflammation. The main goal of PSA testing is early detection of potential prostate cancer before symptoms appear. Early detection allows for timely intervention, which can significantly impact treatment outcomes.

Should You Have A PSA test for prostate cancer screening?

Deciding whether to have a PSA test is a personal choice best made with your healthcare provider. Several factors influence this decision, including your age, family history of prostate cancer, ethnicity, and overall health. Men with higher risk factors, such as a strong family history or African American heritage, may benefit from earlier screening. It’s crucial to discuss with your doctor the potential benefits of early detection versus the risks of overdiagnosis and unnecessary treatment. Your healthcare provider can help you make an informed decision based on your individual circumstances.

When should I start PSA Screenings?

Doctors often recommend PSA testing in men 55 and older. However, your doctor may recommend testing your levels at an earlier age if you have known risk factors for prostate cancer, including family history of the disease or the known presence of a germline mutation.

Understanding your PSA results

In general, doctors often consider PSA levels of 3.9 ng/mL and lower to be normal depending on your age. It is also important for your doctor to track any increases in your PSA levels as these increases may suggest the presence of cancer even if your PSA is in the normal range.

According to American Cancer Society, men with a PSA level between 4.0 and 10.0 ng/mL have a 25% chance of having prostate cancer. For men with a PSA level greater than 10.0 ng/mL, the chance of prostate cancer is over 50%.1

Consult with your physician regarding PSA results and PSA ranges.

What are normal PSA test results?

While PSA levels under 4.0 ng/mL are typically considered normal for most men, it’s important to note that “normal” can vary with age. Older men may naturally have higher levels. Your doctor will interpret your results in the context of your overall health and risk factors.

As mentioned above, a high PSA doesn’t always mean a man has prostate cancer. PSA levels can be elevated because of several benign conditions.

Your healthcare provider will consider various factors when interpreting your PSA test results.

The next steps if your test shows elevated PSA levels

If your PSA test shows higher-than-expected levels, your doctor will likely recommend additional steps to determine the cause. These may include:

  • Repeating the PSA test to confirm the results
  • Performing a digital rectal exam (DRE)
  • Ordering imaging tests
  • Considering a prostate biopsy
  • Recommending genetic testing, especially if you have a family history of prostate or related cancers

Your healthcare provider will guide you through these options, taking into account the degree of PSA elevation, your individual health profile, and your family history. Prostate cancer genetic testing can provide valuable insights into your cancer risk and may influence further diagnostic and treatment decisions. Remember, elevated PSA levels don’t automatically mean you have cancer, but they do warrant further investigation.

What are other reasons why PSA levels may have risen?

  • Age
    It is normal for PSA levels to increase gradually with age.
  • Men over 50: BPH
    Benign prostatic hyperplasia (BPH) is an enlargement of the prostate gland, but it is not prostate cancer. BPH is another common prostate problem in men over age 501. It may not need to be treated unless it causes frequent, difficult urination or other urinary symptoms. Your primary care doctor may be able to tell the difference between BPH and prostate cancer by doing a digital rectal exam (DRE), but commonly this will require evaluation by a urologist and further testing, such as a biopsy or imaging studies.2
  • Prostatitis: A Common Problem in Men Under 50
    Prostatitis is the most common prostate problem for men younger than 50.2 Prostatitis caused by bacteria is treated with antibiotics. Another, more common type of prostatitis, called nonbacterial prostatitis, can be harder to treat and may last a long time.2
  • Medical Procedures
    Any of the following medical procedures could potentially lead to a rise in PSA:
    • Prostate Biopsy
    • Transurethral Resection of the Prostate (TURP)
    • Urethral Catheter
    • Cystoscopy
    • Or any other procedure that involves the prostate. If you have had any of the above medical procedures or conditions, you should consult your physician to see if you should wait before having your PSA test.
  • A Digital Rectal Exam (DRE)
    To avoid this type of elevation, doctors will usually draw blood for a person’s PSA level prior to conducting a rectal exam.
  • Urinary Tract Infection
    If you have been diagnosed with a urinary tract infection, this could irritate or inflame the prostate cells that could lead to a result of a falsely elevated PSA. Be sure to wait until after the infection has cleared up before getting a PSA test. In men, most urinary tract infections are caused by bacteria and respond well to antibiotics.
  • Sexual Activity
    Participating in a sexual activity that involved ejaculation within about 48 hours before testing can affect PSA results.
  • Certain Medications and Supplements
    Medications such as aspirin, statins, nonsteroidal anti-inflammatory drugs, or medication for urinary problems have the potential to affect PSA levels. Sport or nutritional supplements such as testosterone can cause PSA levels to rise.
  • Riding a Bicycle
    There have been studies that suggest cycling may raise PSA. The studies mention the rise may be due to the seat putting pressure on the prostate. It should be noted that not all studies have found this to be true.
  • Prostate Cancer
    Having a high PSA result when paired with other screening tests, including DRE, can be an indication you may be at risk for prostate cancer, which can result in your doctor recommending a biopsy to confirm a prostate cancer diagnosis.

The benefits and limitations of PSA tests

PSA testing offers both advantages and potential drawbacks. It’s important to discuss these with your healthcare provider to make an informed decision about screening.

Benefits of the PSA test

  • Early Detection: PSA tests can help identify prostate cancer in its early stages, often before symptoms appear. This early detection can lead to more effective treatment and improved outcomes.
  • Risk Assessment: For men at higher risk of prostate cancer, regular PSA testing provides valuable information to guide healthcare decisions.
  • Peace of Mind: Normal PSA results can offer reassurance, particularly for those with elevated risk factors.

Limitations of the PSA test

  • Lack of Specificity: Elevated PSA levels do not always indicate cancer. Other conditions, such as benign prostatic hyperplasia (BPH) or prostatitis, can also raise PSA levels.
  • False Positives: PSA tests may sometimes suggest cancer when it’s not present, potentially leading to unnecessary anxiety and additional testing.
  • Overdiagnosis: Some slow-growing cancers detected by PSA testing may never cause harm or require treatment. However, their discovery could lead to unnecessary interventions.
  • Potential Overtreatment: Treating slow-growing or non-threatening cancers can lead to side effects that might outweigh the benefits of treatment.

Remember, PSA testing is just one tool in prostate health management. Your doctor can help you weigh these factors based on your individual health profile and risk factors.

Other prostate cancer screenings

Digital Rectal Exam (DRE)

A Digital Rectal Exam (DRE) is another important screening tool for prostate cancer. During this in-office procedure, your doctor examines the prostate gland by inserting a lubricated, gloved finger into the rectum. This allows them to feel for any abnormalities or enlargement of the prostate.

What to expect:

  • The exam is brief but may cause temporary discomfort
  • You might feel the urge to urinate due to pressure on the prostate
  • Not all areas of the prostate can be felt during a DRE

If your PSA levels or DRE results raise concerns, your doctor may recommend further testing.

Prostate biopsy

A prostate biopsy is typically performed to confirm the presence of cancer when PSA levels are elevated, or a DRE reveals abnormalities. This procedure involves taking small tissue samples from your prostate for examination.

What to expect:

  • Your doctor will provide specific pre-biopsy instructions
  • The procedure often uses ultrasound guidance (TRUS)
  • Several core samples are taken from different areas of the prostate
  • The samples are sent to a lab for analysis

Gleason Scoring

If cancer is found in your biopsy samples, pathologists use Gleason scoring to grade the cancer’s aggressiveness. This scoring system is crucial for determining appropriate treatment options.

How it works:

  • Cancer cells are assigned two grades from 1 to 5 based on their appearance
  • These grades are added together to get a Gleason score (2-10)
  • Most prostate cancers score between 6 and 10
  • Higher scores generally indicate more aggressive cancer

Example: A Gleason score of 3+4=7 means the primary pattern is grade 3, and the secondary pattern is grade 4.

It’s important to note that while Gleason scoring is valuable, it has limitations. Scoring can be subjective and may vary between pathologists. Your doctor might recommend additional testing, such as the Prolaris test, for a more comprehensive assessment of your cancer’s aggressiveness.

Remember, these screening methods work together with PSA testing to provide a fuller picture of your prostate health. Always discuss the results and their implications with your healthcare provider.

A Prolaris Score can help you and your doctor move forward with confidence to make the best treatment decision.

References
  1. https://www.cancer.org/cancer/prostate-cancer/early-detection/tests.html
  2. https://www.everydayhealth.com/prostate-cancer/non-cancerous-reasons-your-psa-levels-are-high.aspx

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