The Prostate-Specific Antigen (PSA) test is a blood analysis used to screen and monitor the health of the prostate gland. This test measures the amount of a specific protein, PSA, circulating in the bloodstream. PSA is produced exclusively by cells within the prostate, a small gland situated beneath the bladder. Healthcare providers utilize the results to monitor changes that may prompt further investigation.
Understanding Prostate Specific Antigen
Prostate-Specific Antigen is a serine protease enzyme naturally produced by the epithelial cells of the prostate gland. The primary function of PSA is related to male fertility, specifically helping to liquefy the semen after ejaculation to allow sperm to move freely. A small amount of this protein naturally leaks from the prostate into the bloodstream, and the concentration measured is what the PSA test reports.
The PSA measurement typically reported is the Total PSA, which represents the overall concentration of the protein in the blood. PSA exists in two forms in the circulation: a portion bound to other proteins and a portion that circulates freely. The measurement of Free PSA, or the unbound portion, becomes important when Total PSA is moderately elevated (usually between 4 and 10 nanograms per milliliter (ng/mL)). A lower percentage of Free PSA relative to Total PSA is associated with a higher likelihood of prostate cancer.
Age-Specific PSA Levels for Older Men
The concept of a single “normal” PSA value for all men has been replaced by age-specific guidelines, particularly for older individuals. PSA levels tend to increase naturally as men age, even in the absence of disease. This rise is primarily due to the natural, non-cancerous growth of the prostate gland, which causes more PSA to filter into the bloodstream.
For men in their 80s, the acceptable range is significantly higher than the traditional 4.0 ng/mL cutoff used for younger men. Many clinicians consider a PSA level up to 6.5 ng/mL to be within the appropriate range for men over 70 years old. Some population studies suggest that the upper limit of the expected range can be as high as 7.28 ng/mL for men over 80.
The interpretation of a specific PSA number for an 80-year-old is highly individualized and depends heavily on overall health and life expectancy. For a man in his 80s, a PSA of 5.0 ng/mL may be far less concerning than the same level in a 50-year-old. The decision to pursue further testing is often based on the patient’s health status, including whether they have a life expectancy greater than ten years, and the rate of change in their PSA level over time.
Non-Cancerous Reasons for Elevated PSA
An elevated PSA reading should not be automatically interpreted as an indication of prostate cancer, as many benign conditions can cause the level to rise. The most frequent non-cancerous cause of a mild to moderate PSA elevation in older men is Benign Prostatic Hyperplasia (BPH). BPH is the age-related enlargement of the prostate, which produces more PSA that enters the circulation.
Another common cause of a temporary spike in PSA is prostatitis, which is the inflammation or infection of the prostate gland. This inflammation can be bacterial or non-bacterial, causing the prostate cells to release a large amount of PSA into the blood. A urinary tract infection (UTI) can also cause a significant but transient elevation in the PSA level.
Several temporary activities or procedures can cause the PSA level to be artificially high at the time of the blood draw. Recent ejaculation, for example, can temporarily elevate the level, which is why abstinence for two to three days before the test is often recommended. Similarly, a recent digital rectal examination (DRE) or the use of a urinary catheter can cause a brief rise due to physical manipulation.
Interpreting Results and Subsequent Testing
When an 80-year-old man has an elevated PSA level, the clinician often employs secondary metrics to refine the assessment of risk. One such tool is PSA density (PSAD), calculated by dividing the PSA value by the volume of the prostate gland. A high PSAD suggests that the PSA production is disproportionate to the gland’s size, potentially indicating a higher risk.
Another important metric is PSA velocity (PSAV), which tracks the rate at which the PSA level changes over a period of time. A rapid increase in PSAV may be more concerning than a single high reading, even if the absolute PSA number remains within an acceptable range for the patient’s age. These secondary tests are used alongside the percentage of Free PSA to decide if a prostate biopsy is warranted.
For older men diagnosed with low-risk, slow-growing prostate cancer, the preferred management strategy is often Active Surveillance. This approach involves regular monitoring with periodic PSA tests, DREs, and sometimes repeat biopsies, rather than immediate aggressive treatment. Active Surveillance is chosen to avoid the potential side effects of surgery or radiation, such as urinary incontinence and erectile dysfunction. For frail men with significant other health issues, a less intensive approach known as Watchful Waiting may be recommended.