For men in their early seventies, most urologists consider a PSA (prostate-specific antigen) level somewhere below about 6.5 ng/mL to be within the age-adjusted reference range, though the traditional cutoff of 4.0 ng/mL still dominates clinical practice. The honest answer is that no single number cleanly separates “normal” from “abnormal” at age 73, and the original 4.0 threshold was never designed with older men in mind. What matters more than any snapshot number is how your PSA fits into a broader picture that includes your health, life expectancy, and whether acting on the result would actually help you.
Where the 4.0 Cutoff Came From and Why It Fits Poorly at 73
The 4.0 ng/mL threshold that most people have heard of was set decades ago using a study population that was overwhelmingly younger than the men who actually get screened. Of the roughly 470 men used to establish that reference value, only about 55 were between 50 and 59, and fewer than 20 were 60 or older.1Oncology. Age-Specific Reference Ranges for PSA in the Detection of Prostate Cancer In other words, the number that defines “normal” for you was largely derived from men two decades younger, whose prostates were smaller and less likely to have the benign enlargement that pushes PSA upward with age.
PSA is a protein produced by both normal and cancerous prostate tissue. As the prostate grows over the years, it simply makes more PSA. Population studies consistently show a clear upward trend: men in their fifties typically have lower median PSA values than men in their sixties, who in turn have lower values than men in their seventies.2PubMed Central. Age-specific reference ranges of prostate-specific antigen in the elderly of Amirkola: A population-based study This is why researchers developed age-specific reference ranges in the first place. For men aged 70 to 79, the commonly cited upper limit is around 6.5 ng/mL. A 73-year-old man with a PSA of, say, 5.2 would be flagged as abnormal under the old 4.0 rule but would fall within the age-adjusted range. Whether that distinction matters depends on the clinical context.
Should a 73-Year-Old Be Getting PSA Tests at All?
This is the question that often gets skipped, and it is more important than the number itself. The U.S. Preventive Services Task Force explicitly recommends against routine PSA-based screening in men 70 and older.3JAMA. Prostate Cancer: Screening That recommendation is not because prostate cancer stops being dangerous at 70. It is because screening at this age is far more likely to find slow-growing cancers that will never cause symptoms than to catch the aggressive ones early enough to make a difference. Most international guidelines follow a similar pattern, varying the upper screening age from roughly 70 to 75 and tying the decision to estimated life expectancy, with thresholds ranging from about 7 to 15 remaining years.4PubMed Central. Screening asymptomatic men for prostate cancer: A comparison of international guidelines on prostate-specific antigen testing
Most guidelines do not recommend screening in elderly men with limited life expectancies because the known harms tend to outweigh the potential benefits.5PubMed. PSA screening among elderly men with limited life expectancies That said, “limited life expectancy” is not the same as “age 73.” A healthy 73-year-old with no major chronic conditions might reasonably have another 15 years ahead. A 73-year-old with heart failure and diabetes might not. The guideline is really about biology, not birthday candles. If your doctor has been tracking your PSA for years and you are in good health, the conversation is different than if someone orders a PSA test for the first time at 73 with no prior baseline.
The Overdiagnosis Problem After 70
The core concern with screening older men is not that PSA testing is inaccurate. It is that it works too well at finding cancers that would never have caused trouble. Nonselective PSA testing followed by liberal biopsy criteria has resulted in a high rate of overdiagnosis, which is one of the major obstacles to population-based screening programs.6PubMed. Overdetection in screening for prostate cancer
The problem is especially pronounced in men over 70. Long-term follow-up from the European Randomized Study of Screening for Prostate Cancer (ERSPC) found no mortality benefit from PSA screening for men aged 70 to 74, with a hazard ratio of 1.06, essentially no difference from the unscreened group.7PubMed Central. Evaluating the impact of age on prostate cancer overdiagnosis using long-term follow-up from a randomised trial Prostate cancer typically has a long lead time between detection and the point where early treatment would have mattered. By the time a cancer detected at age 73 might become lethal, competing causes of death from cardiovascular disease, other cancers, or simply aging often get there first. Modeling studies confirm that stopping screening when PSA is low at age 60 or older reduces overdiagnosis substantially while only modestly reducing lives saved.8PubMed Central. Lifetime Benefits and Harms of Prostate-Specific Antigen–Based Risk-Stratified Screening for Prostate Cancer
None of this means a 73-year-old should ignore a significantly elevated or rapidly rising PSA. It means that finding a slightly elevated number in a routine blood panel is a different situation from having symptoms or a strong family history. The decision to pursue further testing should account for what you would actually do with the information.
What Pushes PSA Up Besides Cancer
One reason a single PSA number is hard to interpret is that many things besides prostate cancer raise it. Benign prostatic hyperplasia, the age-related prostate enlargement that affects most men by their seventies, is the most common cause of a mildly elevated PSA. Prostatitis, urinary tract infections, recent ejaculation, vigorous cycling, and even a digital rectal exam can temporarily bump the number up. A 73-year-old man whose PSA comes back at 5 or 6 ng/mL has a high probability that the elevation reflects a larger-than-average prostate rather than malignancy.
Ethnicity also plays a role. A systematic review of studies in cancer-free men found that Black men tend to have higher baseline PSA levels than white men, and this difference appears even in younger populations without prostate disease.9Prostate Cancer and Prostatic Diseases. Ethnic differences in prostate-specific antigen levels in men without prostate cancer: a systematic review Research comparing Chinese, African American, and Caucasian American men confirmed differences in baseline PSA and the rate at which PSA rises over time.10PubMed. Characteristics of baseline PSA and PSA velocity in young men without prostate cancer: Racial differences These differences mean that a “normal” PSA of 4.5 might carry different implications depending on your background, and that a single universal cutoff fits some populations better than others.
Medications That Change Your PSA
Two categories of common drugs can meaningfully alter PSA levels, and if you are 73, there is a good chance you are taking one of them.
The first is 5-alpha reductase inhibitors, sold as finasteride (Proscar) and dutasteride (Avodart), which are widely prescribed for benign prostate enlargement and hair loss. Finasteride cuts PSA roughly in half within the first year of use. After that initial drop, PSA continues to decline at about 2% per year while men not taking the drug see an annual increase of about 3%.11PubMed. Long-term effects of finasteride on prostate specific antigen levels: results from the prostate cancer prevention trial Data from the Prostate Cancer Prevention Trial found that the adjustment factor needed to estimate a man’s “true” PSA while on finasteride increased from about 2 at two years to 2.5 at seven years of use. If you are taking finasteride and your doctor does not account for this, your PSA could look reassuringly low even when something warrants attention. Always make sure your doctor knows you are on one of these drugs before interpreting a PSA result.
The second category is testosterone replacement therapy. PSA rises modestly with testosterone treatment. A controlled trial in older men with low testosterone found that PSA increased by an average of about 0.47 ng/mL over 12 months in the treatment group, compared to 0.06 ng/mL in the placebo group.12The Journal of Clinical Endocrinology & Metabolism. Prostate-Specific Antigen Levels During Testosterone Treatment of Hypogonadal Older Men: Data from a Controlled Trial A separate randomized trial confirmed the PSA bump but found that the difference between groups mostly leveled off after the first year.13JAMA Network Open. Prostate Safety Events During Testosterone Replacement Therapy in Men With Hypogonadism: A Randomized Clinical Trial The effect is small on average but variable, meaning some men on testosterone see a larger spike than others. Men on testosterone replacement should expect regular PSA monitoring.14PubMed Central. Rising PSA during Testosterone Replacement Therapy
Refining the PSA Number
When a PSA level falls in the ambiguous range, roughly between 4 and 10 ng/mL, doctors have several ways to sharpen the picture before jumping to a biopsy. These refinements matter at every age but are especially relevant for a 73-year-old, where the stakes of an unnecessary biopsy are higher and the stakes of overdiagnosis loom larger.
Free-to-total PSA ratio. PSA circulates in the blood in two forms: bound to proteins and free-floating. Cancer tends to produce more of the bound form, so a lower percentage of free PSA raises suspicion. A large multicenter trial found that using a 25% free PSA cutoff caught 95% of cancers while avoiding about 20% of unnecessary biopsies in men with total PSA between 4.0 and 10.0.15PubMed. Use of the percentage of free prostate-specific antigen to enhance differentiation of prostate cancer from benign prostatic disease: a prospective multicenter clinical trial The free-to-total ratio was a stronger independent predictor of cancer in that range than either age or total PSA alone. Other research found that the diagnostic accuracy of the free-to-total ratio was substantially better than total PSA on its own in the gray zone, with overall accuracy around 92% versus about 61%.16TAJ: Journal of Teachers Association. Ability of Free/Total Serum PSA Ratio in Diagnosing Prostate Cancer and Benign Prostatic Hyperplasia
PSA density. This is your PSA level divided by the volume of your prostate, measured by ultrasound or MRI. A large prostate making a lot of PSA is less worrisome than a small prostate making the same amount. PSA density performs well at distinguishing benign enlargement from cancer in the gray zone, with one study finding that a density cutoff of 0.13 ng/mL per cubic centimeter achieved sensitivity and specificity above 90%.17PubMed Central. Prostate-Specific Antigen Density: A Measurement to Differentiate Benign Hypertrophy of Prostate from Prostate Carcinoma PSA density measurements are also useful in gauging the aggressiveness of cancers that are found, helping predict which ones are clinically insignificant and which require intervention.18PubMed. Prostate specific antigen density correlates with features of prostate cancer aggressiveness
PSA velocity. How quickly your PSA is rising over time often matters more than any single reading. A sharp jump over a year or two is more concerning than a gradual creep that tracks with slow prostate growth. This is one reason having prior PSA values on record is useful and why a first-ever PSA test at 73 is harder to interpret than one that fits into a multi-year trend.
Newer Tests and MRI
If standard PSA refinements still leave the picture unclear, a growing menu of additional tools can help decide whether a biopsy is justified. Blood-based panels like the 4Kscore combine four kallikrein protein markers with clinical information to estimate the probability of finding aggressive cancer on biopsy. In a prospective U.S. trial of over a thousand men, the 4Kscore accurately predicted biopsy results for higher-grade cancers.19PubMed Central. Finding the Wolf in Sheep’s Clothing: The 4Kscore Is a Novel Blood Test That Can Accurately Identify the Risk of Aggressive Prostate Cancer A head-to-head comparison of the 4Kscore against another commercially available test, SelectMDx, found the 4Kscore had stronger discriminatory ability for clinically significant cancer.20PubMed. Concordance and Performance of 4Kscore and SelectMDx for Informing Decision to Perform Prostate Biopsy and Detection of Prostate Cancer
Multiparametric MRI of the prostate has become increasingly common before biopsy. Clinical guidelines now generally favor obtaining an MRI before proceeding to tissue sampling.21PubMed Central. Trends in pre-biopsy MRI usage for prostate cancer detection, 2007-2022 Compared with standard biopsy alone, MRI-guided approaches have detected more clinically significant cancers and fewer clinically insignificant ones in multiple studies.22PubMed Central. The impact of pre-biopsy MRI and additional testing on prostate cancer screening outcomes: A rapid review The technology is not perfect: the negative predictive value ranges from about 76% to 87%, which means a clean MRI does not completely rule out cancer, and the positive predictive value runs between about 27% and 44%, meaning many MRI-flagged areas turn out to be benign.23PubMed. Should men undergo MRI before prostate biopsy – CON Still, for a 73-year-old weighing whether to pursue a biopsy, an MRI that shows nothing suspicious can be genuinely reassuring and may spare a procedure with real side effects.
Researchers are also combining multiple biomarkers into panel-based approaches. One recent study found that integrating the free-to-total PSA ratio, PSA density, and several urinary microRNA markers into a single model produced an overall accuracy above 90% in the gray zone, outperforming any individual marker on its own.24PubMed Central. Multimodal urinary biomarker panel achieves superior prostate cancer detection accuracy and reduces unnecessary biopsies These combined tests are still being validated and are not yet standard practice everywhere, but they point toward a future where a mildly elevated PSA triggers a tiered workup rather than an automatic biopsy recommendation.
What Happens If a Biopsy Is Recommended
Understanding the potential downsides of a prostate biopsy is part of making an informed decision. The most common complications are blood in the urine and rectal bleeding, both of which occur in a sizable minority of men. In one study, blood in the urine appeared in about 40% to 53% of men on the first day after the procedure, and rectal bleeding in roughly 12% to 26%.25PubMed Central. Complication rates after prostate biopsy according to the number of sampled cores Other complications like fever, urinary retention, and pain occurred in a smaller fraction, roughly 3% to 8%. About a third of men reported no complications at all. These numbers are not alarming on their own, but they are real, and for a 73-year-old man whose elevated PSA is more likely to reflect benign growth than dangerous cancer, the risk-benefit math deserves careful thought.
When Cancer Is Found but Treatment May Not Help
If a biopsy does reveal cancer in a 73-year-old, the next question is whether to treat it aggressively. Low-grade prostate cancer in older men is often managed conservatively. Active surveillance involves regular PSA tests, imaging, and periodic biopsies, with treatment triggered only if the cancer shows signs of becoming more aggressive. Watchful waiting is even more hands-off: monitoring for symptoms rather than tracking the cancer closely with repeat biopsies.
Modeling research found that for men aged 65 and older with low-risk prostate cancer, watchful waiting actually yielded more quality-adjusted life years than active surveillance because it avoided the anxiety, repeated biopsies, and side effects of treatment that roughly half of men on active surveillance eventually undergo.26PubMed Central. Active Surveillance Versus Watchful Waiting for Localized Prostate Cancer: A Model to Inform Decisions This runs counter to the instinct that doing more is always better. For younger men, active surveillance clearly wins. For older men with low-risk disease, the evidence supports a lighter touch. By 2021, nearly 60% of men with low-risk prostate cancer were managed conservatively as their initial approach, reflecting a broad shift in how urologists think about this disease.27PubMed Central. Comparing Active Surveillance and Watchful Waiting With Radical Treatment Using Machine Learning Models Among Patients With Prostate Cancer
What to Actually Do With a PSA Result at 73
If you are 73 and get a PSA test back, the number alone tells you surprisingly little. A reading under 4.0 is reassuring by any standard, and a reading between 4.0 and about 6.5 sits within the age-adjusted range for men in their seventies, meaning further investigation is optional rather than urgent. A PSA above 10 warrants attention regardless of age. The gray zone in between is where most of the difficult decisions live.
The most useful thing you can bring to the conversation with your doctor is context. Have you been on finasteride or testosterone? Do you have prior PSA values to compare against? Do you have a family history of prostate cancer, particularly a father or brother diagnosed young? Are you in good enough health that you would choose to undergo treatment if cancer were found? If the answers suggest that finding cancer would change your management, then refining the PSA result with free-to-total ratio, PSA density, or additional biomarker testing makes sense. If you would not pursue aggressive treatment regardless, then the value of chasing a mildly elevated number diminishes considerably, and a frank discussion about watchful monitoring may serve you better than a biopsy.