Is This Prostate Cancer Test 270% Better Than a PSA Test?

“270% better than PSA.”

This headline is compelling. However, such claims require careful scrutiny before they inform medical decision-making.

The claim refers to the EpiSwitch Prostate Screening test, commonly called the PSE test. This blood test combines a man’s PSA result with five epigenetic markers associated with prostate cancer.

The published research presents promising results. However, it does not demonstrate that PSE is 270% superior to PSA for all patients or in every clinical context.

To understand this limitation, it is necessary to examine the test’s measured parameters, the study population, and the variation in results across different patient groups.

The PSE test combines two types of information.

The first is the standard prostate-specific antigen, or PSA, blood test. PSA measures a protein produced by prostate tissue. An elevated PSA could be associated with prostate cancer, but it could also result from benign prostate enlargement, inflammation, infection, ejaculation, cycling, recent instrumentation, or normal variation.

The second part looks for chromosome conformation signatures in the blood. These signatures represent changes in how sections of chromosomes fold and interact. Researchers have identified certain patterns associated with prostate cancer.

The PSE model combines the epigenetic findings with PSA as a continuous number. The result is reported as a positive or negative finding rather than a numerical value you follow over time.

The PSE test does not replace PSA. PSA remains part of the calculation.

The “270% better” statement comes from a statistical comparison called the diagnostic odds ratio.

A diagnostic odds ratio compares the odds of a positive test in someone with the disease against the odds of a positive test in someone without it. Researchers use this measurement to compare diagnostic performance.

It is not the same as saying the test detects 270% more cancers. It does not mean it is 270% more accurate for every patient. It also does not prove a man receiving the test will have a 270% better outcome.

The statement takes one statistical comparison and turns it into a marketing-friendly percentage.

This does not diminish the value of the research. Rather, it highlights the need to interpret the claim within its proper context.

The 2023 study included blood samples from two groups.

The first group included 109 men from the PROSTAGRAM prostate cancer screening pilot study. Of those men, 88 did not have cancer and 21 had cancer.

The second group included 38 patients from Imperial College NHS Trust. This group contained men with established prostate cancer, including organ-confined, locally advanced, and metastatic disease, along with cancer-negative controls.

The researchers evaluated PSA, EpiSwitch, and the combined PSE model.

Across the selected combined dataset, the PSE model produced a positive predictive value of approximately 93%, a negative predictive value of 95%, and an overall accuracy of approximately 94%.

Positive predictive value tells us how often a positive result represented cancer within the study population. Negative predictive value tells us how often a negative result represented the absence of cancer.

These findings warrant further investigation. The combined test outperformed PSA alone within the selected dataset.

The screening group provides a more useful picture of how PSE might perform among men who have not already received a prostate cancer diagnosis.

When the 109 PROSTAGRAM participants were evaluated separately, the PSE test had a positive predictive value of approximately 67%, a negative predictive value of 95%, and an overall accuracy of 92%.

The confidence interval surrounding the positive predictive value was wide, ranging from about 30% to 90%. This occurred because the screening group contained only a small number of cancers.

The PSE test yielded fewer false-positive results than PSA and identified a higher proportion of cancers within the selected screening group. However, the study does not establish a 93% positive predictive value for a general screening population.

The study authors acknowledged this limitation. They recommended further prospective, blinded validation in a larger screening population with a low prevalence of cancer.

Test performance changes based on who receives the test.

A group containing many men with established or advanced prostate cancer is different from a general screening population. When disease is more common in the population being studied, positive predictive value tends to increase.

This is why the combined results should not be applied automatically to every man with an elevated PSA.

The PSE test performed well in the smaller Imperial College group, which contained men with established and higher-risk cancers. The screening group produced encouraging results, but the positive predictive value was lower and less precise.

Both sets of findings are relevant to the overall assessment of the test’s utility.

Oxford BioDynamics, the company behind the EpiSwitch technology, funded the study. Eight listed authors were company employees, one was a company director, and Oxford BioDynamics holds patents related to the technology.

Industry funding does not invalidate a study. Companies often fund research involving their own diagnostic products because they developed the technology and have the resources to study it.

This underscores the importance of independent validation. Before the test is incorporated into routine screening, it is essential to see its performance replicated in larger populations by researchers without financial ties to the product.

A negative PSE result appears reassuring, but it does not reduce the risk of cancer to zero.

In the screening cohort, the negative predictive value was 95%. This means some cancers were still present among participants who received a negative result.

The test also becomes less helpful when interpreted as a one-time verdict. Prostate cancer risk changes over time. A negative result today does not determine what will happen several years from now.

If your PSA remains elevated or begins rising more rapidly, you still need continued monitoring.

PSA has serious limitations when used as a single cancer-detection test. It is produced by prostate tissue, not only prostate cancer cells. A high result does not prove cancer, and a result within the reference range does not exclude it.

Its strength is accessibility and repeatability.

PSA provides a number you can follow over time. One isolated value gives limited information. A series of results allows you to evaluate direction, velocity, variability, and the response to changes in prostate health.

A PSA of 6, followed by 6.2 and 6.1, creates a different clinical picture from a PSA that rises from 6 to 9 to 14.

The number still needs careful interpretation. Prostate size, inflammation, medications, hormonal status, recent activity, laboratory variation, and other factors all influence the result.

The appropriate response is not to discontinue PSA testing, but rather to avoid interpreting a single elevated PSA value as a definitive diagnosis.

The PSE test could provide another layer of information when a man has an elevated PSA and wants more context before deciding what to do next.

A negative result might reduce concern in selected cases. A positive result could support closer evaluation and monitoring. It could also help separate men who have a higher probability of cancer from those whose PSA elevation comes from another source.

The test should not serve as a stand-alone verdict. It does not determine whether a cancer will remain contained, become aggressive, or affect a man’s longevity. It also does not replace the need to look at PSA trends, prostate size, symptoms, health history, imaging findings, and other biomarkers.

PSE costs far more than a standard PSA test. Cost matters because prostate monitoring is not a one-time event.

A man who receives a negative result at age 50 could still have an elevated PSA at 51, 52, or 55. He then faces another decision about whether to repeat the test.

This does not imply that the PSE test is never justified despite its cost. Instead, it is important to consider the specific information sought and how the result will inform subsequent clinical decisions.

Before ordering any advanced biomarker test, ask one question:

What will I do differently based on the result?

If the answer is uncertain, the test may increase costs and anxiety without contributing to improved clinical management.

I consider the PSE test a credible and promising blood test. Its combination of PSA with epigenetic chromosome-conformation markers deserves continued research.

I do not consider the current evidence sufficient to call it 270% better than PSA in the broad way the headline suggests.

The original study was small. The strongest performance numbers came from combining a screening group with a group containing men with established cancer. The screening-only results were encouraging, but they had wide confidence intervals. The research was also funded by the company behind the technology.

These limitations do not negate the potential value of the test. Rather, they inform the degree of confidence that should be placed in the current findings.

The PSE test could become a useful addition to prostate cancer risk assessment. Early results show fewer false positives and improved cancer detection compared with PSA alone in the populations studied.

The PSE test should not be considered a substitute for comprehensive long-term monitoring.

Prostate cancer risk does not exist at a single point in time. You need to evaluate patterns, changes, and the full clinical picture. PSA remains useful because it is inexpensive, accessible, numerical, and easy to repeat.

A prominent percentage in a headline should not be the sole basis for clinical decision-making.

Understand what the statistic measures. Look at the people included in the study. Consider how the result would affect your next step. Then decide whether the added information is worth the cost.

Dr. Stephen Petteruti is a board-certified physician specializing in longevity-focused, integrative medicine. He works with men navigating prostate cancer, testosterone and hormone health, aging, and performance using proactive, evidence-informed strategies grounded in real clinical practice.

Learn more at www.intellectualmedicine.com and www.drstephenpetteruti.com

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The content in this article reflects the opinions and clinical experience of Dr. Stephen Petteruti and is intended for informational and educational purposes only. It is not medical advice and should not replace guidance from your personal healthcare provider. Always consult your physician before making changes to your health regimen.