Prostate-specific antigen (PSA) is a protein produced by cells within the prostate gland. It is important in the early detection of prostate abnormalities, including cancer.
Regular PSA testing assists healthcare professionals in monitoring prostate health and making informed decisions about further diagnostic or treatment options.
The primary function of PSA in the body is to liquefy the semen, facilitating the movement of sperm during ejaculation. This liquefaction process is vital for reproductive success, ensuring that sperm can move freely and efficiently. While a small amount of PSA enters the bloodstream, elevated levels can indicate potential prostate issues. A blood test measures these levels, aiding in the early detection of prostate conditions.
Understanding the various causes of elevated PSA levels helps for accurate diagnosis and treatment. While elevated PSA can be indicative of prostate cancer, it can also be due to several benign conditions. Regular monitoring and consultation with your urologist can provide a comprehensive assessment.
The PSA test is a simple blood test used to measure the concentration of prostate-specific antigen in the bloodstream. Here’s a step-by-step breakdown of the procedure:
PSA is measured in nanograms per millilitre (ng/mL). The specific “normal” range can vary, but traditionally, a PSA less than 4.0 ng/mL has been considered normal. However, some doctors now use a threshold of 2.5 or 3.0 ng/mL.
PSA levels tend to rise with age. Therefore, age-specific ranges have been developed to interpret PSA levels more accurately:
40-49 years: 0-2.5 ng/mL
50-59 years: 0-3.5 ng/mL
60-69 years: 0-4.5 ng/mL
70 and older: 0-6.5 ng/mL
It’s not just the absolute value of the PSA that’s important, but also how quickly it changes. A rapid rise in PSA levels over time, known as PSA velocity, can be indicative of prostate cancer even if the absolute values are not above the traditional threshold.
This considers the size of the prostate. Two men might have the same PSA level, but if one has a larger prostate, the density (PSA level divided by the volume of the prostate) would be lower, which might be less concerning.
PSA exists in two forms in the blood: free (not bound to proteins) and bound (attached to proteins). A lower percentage of free PSA can indicate a higher risk of prostate cancer. Typically, if the PSA is between 4 and 10 ng/mL, a free-to-total PSA ratio is calculated. A ratio below 10-15% means a higher risk of prostate cancer.
Elevated PSA levels can be indicative of prostate cancer. However, a high PSA alone doesn’t confirm cancer. It merely signals the need for further tests. Biopsies, MRIs, and other diagnostic procedures are often used in conjunction with PSA tests to determine the presence of prostate cancer.
Regular monitoring of PSA levels is instrumental in the early detection of prostate conditions. While elevated PSA can indicate potential issues, consider other factors and undergo additional tests for an accurate diagnosis. Individuals are encouraged to consult with healthcare professionals for a thorough evaluation and personalised advice.
Dr Lee is a urologist and kidney transplant surgeon with a broad-based expertise of all urological disorders
He has subspecialty focus on men’s health and male infertility, and special interest in minimally invasive prostate enlargement therapy and kidney stone treatment. Dr Lee has received numerous awards for service excellence such as the Service With A Heart Award (2006-2008, 2011) and the Singapore Health Quality Service Award (2016).
Prior to entering private practice, Dr Lee served in the public sector for 16 years at SGH, where he initiated dedicated clinics evaluating and treating patients with complex men’s health and fertility issues. He also led the Renal Transplant Program and laparoscopic donor nephrectomy service as Surgical Director.
Apart from clinical work, Dr Lee is active in academia and believes in the importance of grooming the next generation of doctor. He was Senior Clinical Lecturer at NUS’ Yong Loo Lin School of Medicine and currently, Adjunct Assistant Professor at the Duke-NUS Medical School. Dr Lee is also regularly invited to share his experiences locally and regionally through lectures, workshops and surgical demonstrations.
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Yes. Besides the PSA test, the digital rectal exam (DRE) is commonly used. Additionally, newer tests like the PCA3 urine test and the PHI (Prostate Health Index) are emerging as alternatives.
Diet and lifestyle can influence prostate health. High-fat diets and sedentary lifestyles may increase PSA levels, while diets rich in fruits, vegetables, and omega-3 fatty acids might have protective effects.
Some studies suggest a genetic component to PSA levels, with certain genetic markers potentially leading to higher PSA. Family history of prostate conditions can also influence levels.
Elevated testosterone levels can lead to increased PSA levels, as testosterone stimulates the prostate gland to produce more PSA.
Conditions like diabetes may result in lower PSA levels, while medications for heart disease, like statins, can influence PSA readings. Consider these factors when interpreting results.
Frequent PSA testing can lead to overdiagnosis and overtreatment, potentially resulting in unnecessary procedures and their associated risks. Balance the benefits and risks of regular testing.
