Prostate Specific Antigen (PSA) Test: Purpose & Results

Prostate cancer is one of the most common cancers affecting men worldwide. In 2024, the American Cancer Society predicted approximately 299,010 new cases of prostate cancer and about 35,250 deaths from the disease in the United States.

Detecting the disease in an early phase is vital for successful treatment and care. The prostate-specific antigen (PSA) test is one key tool in screening for prostate cancer.

What is the PSA Test?

The PSA prostate test is a simple blood test for prostate health screening. It measures the amount of PSA, a protein produced by the prostate gland (below the bladder in males), in the blood.

PSA is found in both cancerous and noncancerous tissues. Elevated PSA levels can indicate potential issues like prostate cancer, prompting further evaluation.

What is the Purpose of the PSA Test?

The PSA blood test serves several important purposes in prostate health management:

1. Screening for Prostate Cancer: The primary use of the test is to screen for prostate cancer by measuring PSA levels in the blood.
2. Monitoring Prostate Health: It monitors changes in PSA levels over time, aiding in the early detection of prostate-related issues.
3. Assessing Treatment Response: After prostate cancer diagnosis or treatment, the PSA test helps determine the effectiveness of interventions and monitor for recurrence.
4. Identifying Other Prostate Conditions: Elevated PSA levels can also indicate noncancerous conditions such as prostatitis or benign prostatic hyperplasia (BPH).

What are the Factors Affecting PSA Levels?

Several factors can influence PSA levels, impacting the interpretation of PSA test results:

1. Age: PSA levels increase with age, influencing what’s considered normal.
2. Prostate Conditions: Prostatitis and BPH can lead to high PSA levels.
3. Prostate Procedures: Biopsy or surgery can temporarily raise PSA levels.
4. Medications: Certain drugs, like those for BPH or testosterone therapy, can affect PSA levels.
5. Sexual Activity: Recent ejaculation can temporarily cause high PSA levels.
6. Physical Activity: Strenuous exercise or pressure on the prostate can impact PSA levels.

What is the Test Procedure for the PSA Test?

The PSA prostate test is a straightforward procedure, that includes:

1. Blood Sample Collection: A blood sample is drawn from a vein, typically in the arm, using a needle.
2. Sample Analysis: This sample is sent to a laboratory for analysis, where technicians measure the level of PSA in nanograms per millilitre (ng/mL).
3. Results Reporting: The PSA-level results are reported to the healthcare provider, who then discusses the findings with the patient.
4. Follow-Up Actions: Based on the PSA levels and other clinical factors, healthcare providers may recommend further evaluation, such as a digital rectal exam (DRE) or prostate biopsy, to confirm findings and guide treatment decisions.

What are the Precautions for the PSA Test?

1. Avoid ejaculation for at least 48 hours before the test.
2. Refrain from vigorous activities that may affect PSA levels.
3. Inform the healthcare provider about medications taken.
4. Schedule the PSA blood test when not experiencing urinary symptoms or infections.
5. Discuss complete health history, including prostate-related conditions.
6. Follow specific instructions given by the healthcare provider before the test.

How to Interpret PSA Results?

The normal PSA levels can vary based on age, with recommended upper limits. The PSA levels by age are as follows:

1. Age 40–49: PSA upper limit of 2.5 ng/mL
2. Age 50–59: PSA upper limit of 3.5 ng/mL
3. Age 60–69: PSA upper limit of 4.5 ng/mL
4. Age 70–79: PSA upper limit of 6.5 ng/mL

Research also suggests differences in PSA levels among racial and ethnic groups. This emphasises the need for individual factors and discussions with healthcare providers for accurate PSA blood test interpretation and decision-making.

What are the Risks Associated with the PSA Test?

1. False Positives: Elevated PSA levels can occur due to noncancerous conditions such as benign prostatic hyperplasia (BPH) or prostatitis, leading to unnecessary anxiety or further testing.
2. False Negatives: In some cases, PSA levels may be normal even when prostate cancer is present, resulting in a false sense of security.
3. Overdiagnosis and Overtreatment: PSA testing may detect slow-growing or non-aggressive prostate cancers that may not require immediate treatment. However, this can lead to overdiagnosis and overtreatment, exposing individuals to potential side effects of unnecessary interventions.
4. Psychological Impact: Abnormal PSA test results can cause emotional distress and anxiety, impacting overall well-being and quality of life.

Although the PSA test for prostate is helpful for screening, it’s not a diagnostic tool. Based on PSA test results and other clinical factors, additional tests, such as a digital rectal exam (DRE) and prostate biopsy, may be recommended.

It is essential to talk with a doctor about risks, family history, and lifestyle. Working together enables informed decisions and promotes better health management.

FAQs

1. What happens if PSA is positive?

If PSA is positive, further tests like a biopsy are done to confirm cancer or identify other prostate issues.

2. What level of PSA indicates cancer?

PSA levels above 4.0 ng/mL typically indicate a higher risk of prostate cancer, but further evaluation is needed.