The Prostate-Specific Antigen (PSA) test is a common blood screening tool used to assess the health of the prostate gland. This test measures the level of a specific protein produced by prostate cells, providing a numerical value that can indicate changes within the gland. An elevated PSA result suggests a need for further investigation but does not automatically diagnose a specific condition. Interpreting this result requires considering the patient’s age, particularly for men in their seventies, where the definition of a “high” result is more nuanced. This article provides general information and should not substitute for professional medical guidance.
Understanding the Prostate-Specific Antigen Test
Prostate-Specific Antigen is a protein primarily produced by the epithelial cells lining the prostate gland. Its biological function is to help liquefy semen following ejaculation, but small amounts naturally leak into the bloodstream. The PSA test measures this concentration in nanograms per milliliter (ng/mL) of blood.
The most commonly ordered test is the total PSA, which measures both bound and free circulating protein. While total PSA is the initial screening measurement, the ratio between the two forms, known as percent-free PSA, is valuable in later diagnostics. Measuring PSA allows clinicians to monitor the prostate for conditions that cause the gland’s cells to produce or release more of this protein into circulation.
Defining Elevated Levels in Men Aged 70
The traditional benchmark for an elevated PSA was historically set at 4.0 ng/mL, but this single cutoff is now considered outdated, especially for older men. Prostate size naturally increases with age due to Benign Prostatic Hyperplasia (BPH), a non-cancerous condition. Since larger prostates contain more cells, they inherently produce and release more PSA, meaning a slightly higher level is expected in men in their seventies.
Medical guidelines now utilize age-specific reference ranges to prevent unnecessary biopsies in older men. For men aged 70 to 79, a generally accepted upper limit for the total PSA is often placed around 6.5 ng/mL for white men. This threshold acknowledges the natural growth of the gland, treating a value that would be considered high in a younger man as potentially normal in a man over seventy.
A single, universal standard does not exist, and ranges can vary based on guidelines and ethnicity. A PSA level is considered high when it significantly exceeds these age-adjusted thresholds or shows a rapid increase over time. A value substantially above 6.5 ng/mL, particularly anything approaching or exceeding 10 ng/mL, warrants prompt and thorough investigation, regardless of age.
Factors Beyond Cancer That Influence Results
Many factors unrelated to malignancy can cause a temporary or sustained elevation in a man’s PSA level. The most common cause of sustained elevation in a 70-year-old is Benign Prostatic Hyperplasia (BPH). BPH causes the prostate gland to enlarge, leading to a higher volume of PSA-producing tissue, but it is not a form of cancer.
Prostatitis, which is inflammation or infection of the prostate, can cause a significant, temporary spike in PSA levels. Other irritations, such as a urinary tract infection, recent manipulation of the prostate (like a digital rectal exam or catheterization), or even recent ejaculation or vigorous exercise, can lead to a transient rise in the protein’s release.
Physicians typically account for these possibilities by inquiring about recent activities or symptoms of infection before interpreting a result. Ruling out these benign causes is a standard step before considering more serious diagnostic procedures. Certain medications, such as 5-alpha reductase inhibitors used to treat BPH, can also artificially lower a man’s PSA result, requiring a multiplication factor for accurate interpretation.
Follow-Up Procedures After a High Result
If a 70-year-old man receives a PSA result above the age-specific threshold, the first step is often to repeat the blood test after a few weeks to confirm the elevation. If the level remains elevated, a physician will look at the PSA velocity, which measures the rate of change over time. A rapid rise, such as an increase greater than 0.75 ng/mL per year, is more concerning than a single high but stable value.
The percent-free PSA test may be used if the total PSA falls into the “gray zone,” typically between 4 and 10 ng/mL. PSA circulates either bound to proteins or as free molecules; a lower percentage of free PSA suggests a higher likelihood of cancer, with a ratio below 18% often prompting further action. Another valuable metric is PSA density, which divides the PSA value by the prostate volume to assess the concentration of the protein.
Further diagnostic steps may include advanced imaging, such as a multi-parametric Magnetic Resonance Imaging (mpMRI) of the prostate, to identify suspicious areas. If imaging reveals concerning features, a targeted biopsy may be recommended, often fused with the MRI images for accurate sampling. The decision to proceed with invasive procedures must be personalized, carefully weighing the patient’s overall health and life expectancy against the potential risks and benefits of diagnosis and treatment.