Prostate-Specific Antigen (PSA) testing measures the amount of PSA found in the blood. PSA is a protein produced in the ducts of the prostate, a gland that is located below the bladder and surrounding the urethra. PSA is released with semen to make the fluid runnier, which helps sperm travel more easily.
Why is PSA testing done?
PSA is mainly found in the semen but is also absorbed in the bloodstream. Elevated PSA levels in the blood is common in men with prostate cancer, benign prostatic hyperplasia (BPH), and prostatitis (infection of the prostate). The PSA test is recommended for cancer screening, to monitor if prostate cancer has returned, or aid in diagnosing a non-cancerous prostate condition.
Normal levels of PSA
Normal blood levels of PSA for an average man can range from 0 to 4 nanograms per milliliter (ng/ml). However, levels may vary over time with prostate size and age. Recent studies have also shown that some men diagnosed with prostate cancer have low levels of PSA while men who do not have prostate cancer have high levels of PSA. A man’s PSA level can also increase if a urinary tract infection is present.
Therefore, PSA testing alone is not an accurate indicator of whether cancer or other prostate conditions are present. Rather, it’s used as a preliminary source of information or combined with other tests such as a Digital Rectal Exam (DRE).
What if your PSA levels are high?
If the tests show an elevated level of PSA, additional testing may be required, including:
- Serial PSA Testing – To monitor possible irregularities and changes that occur over time.
- Free and Bound PSA – Free PSA means the protein circulates within the blood freely and Bound PSA means the PSA is attached to other proteins.
- PSA Density (PSAD) – Looks at the PSA in the blood in relation to the volume of the prostate.
- Nomograms – Encompasses a variety of factors to help predict an outcome, from age to ethnicity, symptoms and more.
Your doctor may also consider other factors when evaluating your PSA scores, including your age, the size of your prostate gland, and if you are taking medications that can affect PSA levels.
The benefits of a PSA test
A PSA test is a simple, non-invasive blood test to screen for cancer. The results can help your doctor determine whether you need further testing, such as a biopsy, Digital Rectal Exam (DRE) or a Magnetic Resonance Imaging (MRI) scan.
Early detection of cancer is important, as it can be treated more successfully before it spreads to other areas of the body and causes serious symptoms. Early treatment reduces the risk of side effects that greatly impact a man’s quality of life, such as erectile dysfunction and incontinence.
Is PSA testing right for you?
PSA testing may not be the right plan of action for everyone as there are some limitations with the test. Your doctor may recommend the test if you meet certain risk factors for prostate cancer such as:
- Age – Men over the age of 50 are at a higher risk of prostate cancer.
- Race – African-American men are at a higher risk of prostate cancer.
- Family genetics – Men with a close family member, such as a father or brother, diagnosed with prostate cancer are at a higher risk of developing the disease.
- Genetics – Inherited gene mutations increase the risk of cancer. The gene mutations associated with prostate cancer are BRCA1 and BRCA2.
- Diet – Consuming a diet high in animal fats and low in vegetables may increase your risk of prostate cancer.
Talk to your doctor about your risks for prostate cancer and medical screenings that are right for you.
1. National Cancer Institute. (2011, August). Understanding Prostate Changes. Retrieved from: http://www.cancer.gov/types/prostate/understanding-prostate-changes/prostate-booklet.pdf.
2. Canadian Cancer Society. (2020). Prostate-Specific Antigen (PSA) Test. Retrieved from: https://www.cancer.ca/en/cancer-information/diagnosis-and-treatment/tests-and-procedures/prostate-specific-antigen-psa/?region=on