"This Prostate Cancer Test is 270% Better Than PSA" – Med Man Explains EpiSwitch® PSE

Last updated: 18 Dec 2025

Dr Quinn, a popular NHS doctor and YouTube educator known as “Med Man,” has released a thoughtful and highly accessible video explaining what the EpiSwitch PSE blood test is, how it works, and why it is poised to change the way we test for prostate cancer. In under four weeks, the video has been viewed more than 430,000 times, with hundreds of comments and shares from men and families wanting more accurate and clearer answers about prostate cancer risk.

Why the standard PSA isn't a “cancer test”

In his video, Dr Quinn starts by explaining a limitation of the familiar PSA (prostate-specific antigen) blood test. PSA is often thought of as a prostate cancer test, but it actually measures how abnormal the prostate may be, not whether cancer is present. Dr Quinn explains, “the PSA isn’t really a cancer test at all”. He uses a simple analogy, thinking of the prostate as a big, heavy book. “The PSA test can't open the book, look inside, and read the words. All it can do is weigh the book. If it finds that the book is heavier than normal, thicker than normal, then the PSA test goes up.” However, it does not tell us why the book is heavier. That extra ‘weight’ can be due to many reasons other than cancer, some medical, such as benign prostate enlargement (BPH) or prostatitis, and others more ordinary, such as cycling recently. When PSA is raised, cancer is only one of several possibilities. As Dr Quinn remarks, “it just tells us something's going on with the prostate without telling us what.”

How EpiSwitch PSE is different

Dr Quinn then introduces the EpiSwitch PSE prostate cancer detection blood test, developed by Oxford BioDynamics. Rather than just measuring how big or inflamed the prostate might be, PSE is designed to look for a pattern of biological markers specifically linked to a high likelihood of prostate cancer.

“Instead of just measuring the thickness of the book and the weight of the book like the PSA test does, the PSE test looks inside the prostate and reads the sticky notes that are in there,” explains Dr Quinn. “So, while PSA just tells us something's going on with the prostate, the PSE answers a scarier question. Has cancer left its mark?”

“Here's why this test is so exciting and has huge potential in the real world,” he goes on to say. “Think of what usually happens. We get a PSA test, and the PSA is raised. The chances of that test actually meaning prostate cancer are 30% to 40%, at max. What happens is that man goes for an MRI—maybe even a biopsy—even though chances are he never needed to have that.”

The PSE, which must be ordered by a medical professional, helps to offer a more accurate option. “In early studies, it's been found that men who have a PSA test plus a PSE test correctly identified cancer in 94% of men. 94% of men. That's a huge jump which more than doubles the accuracy of the PSA alone. And unlike PSA, it's much less likely to give you a false alarm.”

This is exactly where EpiSwitch PSE fits into real-world prostate cancer pathways: fewer unnecessary invasive procedures and anxious moments for men who don’t have prostate cancer, and early, targeted investigation for men who are at increased individual risk.

At Oxford BioDynamics, we are actively working with clinical partners, healthcare providers, and insurers to broaden access to EpiSwitch PSE, and support real-world evidence generation, including our recent breakthrough publication with a US urology clinic—read more about the study, which showed up to a 79% reduction in prostate biopsies by using PSE. As with any medical test, decisions about PSA, PSE, scans or biopsies should always be made together with a qualified healthcare professional.

We're grateful to “Med Man” Dr Quinn that he has taken the time to explore how EpiSwitch PSE works and to share that understanding in a clear way that has resonated with his wide audience. As well as watching his video on YouTube, you can also sign up to his newsletter called “Three Apples” for free using the link: https://drquinnmedman.substack.com/about

Disclosure: Dr. Quinn is an independent NHS General Practitioner. He is not affiliated with, employed by, or compensated in any way by Oxford BioDynamics (OBD). His comments reflect his own clinical experience and professional judgment.