The prostate-specific antigen (PSA) test is a common blood screening tool used to assess prostate health, often generating concern when men see an elevated number. For men aged 75, interpreting this number requires understanding how the body changes with age and how medical professionals view screening in this demographic. This article provides clarity on the expected PSA range for a man at this stage of life, moving beyond the simple concept of “normal” or “abnormal.” This context helps guide the conversation about prostate health with a physician.
What Prostate-Specific Antigen Is
Prostate-specific antigen is a protein enzyme produced almost exclusively by the cells within the prostate gland. The primary biological role of this protein is to liquefy the seminal fluid, allowing sperm to move freely after ejaculation. While most PSA remains in the semen, a small amount leaks into the bloodstream, where it is measured with a blood test.
The PSA test measures the concentration of this protein in nanograms per milliliter of blood (ng/mL). PSA is an organ-specific marker, meaning it indicates activity within the prostate, but it is not a cancer-specific marker. A high level suggests that more protein is escaping into the blood, which can be caused by cancer or several non-cancerous conditions.
Expected PSA Ranges for 75-Year-Old Men
The concept of a single “normal” PSA level is outdated because the prostate gland naturally changes and grows larger as a man ages. This common, often benign growth produces more PSA, leading to a higher baseline level in the blood. Consequently, a level considered concerning in a younger man may be expected in a man aged 75.
For men aged 70 and older, clinicians adopt a higher threshold for concern, acknowledging these physiological changes. While ranges vary between medical groups, a widely cited upper limit for men aged 70 and beyond is often considered to be around 6.5 ng/mL. Other age-adjusted ranges suggest a value up to 5.5 ng/mL may be acceptable for men in the 70 to 80 age bracket.
The main reason for this higher baseline is Benign Prostatic Hyperplasia (BPH), the non-cancerous enlargement of the prostate. Because BPH is prevalent in men aged 75, it causes a physical disruption that allows more PSA to diffuse into the bloodstream. This means a PSA result in the 4.0 to 6.5 ng/mL range is often due to an enlarged but otherwise healthy prostate, rather than a malignancy.
Factors That Temporarily Elevate PSA
When a PSA result returns elevated, it is necessary to look for temporary, non-cancerous factors that may have artificially inflated the number. Prostate infection, known as prostatitis, is a significant cause of elevation, as the resulting inflammation can cause an acute spike in PSA levels. If an infection is present, a physician may prescribe antibiotics and retest the PSA after the condition resolves.
Recent physical manipulation of the prostate can also lead to a short-term increase in the protein’s blood concentration. This includes a digital rectal exam (DRE), a recent prostate biopsy, or catheterization. For the most accurate reading, men are advised to abstain from vigorous exercise, such as cycling, and ejaculation for 48 hours before the test, as these activities can transiently raise the PSA level.
Next Steps After an Elevated Result
If a man aged 75 has a PSA level that remains elevated after accounting for temporary factors, a physician will use detailed assessments to refine the risk. One common approach is analyzing the ratio of free PSA to total PSA. PSA circulates in the blood in two forms: free (unbound) and bound to other proteins. A lower percentage of free PSA relative to the total PSA level suggests a greater likelihood that the elevation is due to cancer rather than benign enlargement.
Another metric is PSA velocity, which measures the rate at which the PSA level has increased over time. A rapid rise, such as an increase greater than 0.75 ng/mL per year, is more concerning than a single high reading, suggesting a quickly progressing issue. Multiparametric Magnetic Resonance Imaging (mp-MRI) is also frequently used before a biopsy. It generates detailed images of the prostate to identify suspicious areas for targeted investigation. A biopsy, the definitive diagnostic test, is typically recommended when these secondary markers and imaging studies indicate a higher probability of clinically significant cancer.
Screening Decisions for Men Over 75
For men over the age of 75, the decision to undergo PSA screening is highly individualized and involves a careful discussion of potential benefits and harms. Major medical organizations, such as the United States Preventive Services Task Force, generally recommend against routine screening for this age group. This recommendation is based on the fact that prostate cancer often grows slowly, and many men in this age bracket have a limited life expectancy due to other health conditions.
The primary concern with screening older men is the risk of overdiagnosis and overtreatment. Detecting a slow-growing cancer that would never have caused symptoms can lead to unnecessary biopsies, surgery, or radiation, which carry risks of complications like urinary, bowel, and sexual side effects. Screening is typically reserved for exceptionally healthy men over 75 who have a projected life expectancy of at least ten years and desire to be screened, acknowledging the potential for both benefit and harm.