By Howard Wolinsky, International Correspondent, The Active Surveillor
Back in 2018, a UK group published the Precision study in the New England Journal. It was a landmark study showing that using MRI first—before biopsy—significantly improves the detection of clinically significant prostate cancer while reducing unnecessary biopsies and the diagnosis of insignificant cancers.
I was excited about it and discussed it with my new urologist. He was skeptical and stressed that he considered the biopsy “the gold standard.” I think his position has softened, but American urologists are still skeptical. Only about one-third of American men with rising PSAs undergo prebiopsy MRI, a fraction of what happens in UK and elsewhere in Europe.
Research came out this month showing that MRIs may play a more prominent role in our care in the years ahead in diagnosing PCa and maintaining Active Surveillance.
Radiologists at University College London Hospital say they can now identify prostate cancer on MRI with such clarity that, in a meaningful number of cases, biopsy may no longer be necessary.
It’s a bold claim—one that challenges decades of dogma—and it will still be challenged by many. It comes from a study published last week in the European Journal of Radiology led by Dr. Alex Kirkham, a consultant radiologist at UCLH.
“We have shown that it is possible,” Kirkham and colleagues write, “to identify a group of patients in whom significant prostate cancer is almost certain.”
In their study of 880 men, the UK team found that a subset of MRI scans were so unmistakably cancerous that every single patient who underwent biopsy in the highest‑certainty category—labeled “99% sure”—was confirmed to have clinically significant disease.
“Only one patient in this group,” they noted, “did not have significant tumour at biopsy.”
For patients, especially those on Active Surveillance, the implications are enormous.
Biopsies have long been the gatekeepers of diagnosis, the unavoidable step between suspicion and certainty. But they come with pain, anxiety, and risks that men know all too well.
The authors acknowledge this directly, writing that prostate biopsy “is only moderately well tolerated and has a small risk of sepsis, urinary retention and sexual dysfunction,” and that in rare cases biopsy has been associated with “extraprostatic extension from tract seeding.”
Even more troubling, biopsies sometimes miss the tumor entirely, leading to false reassurance and delayed treatment. However, MRI has its misses as well, though this can be a feature, not a bug, when it’s low-risk cancer.
Kirkham’s team wanted to know whether MRI could do better—not just as a triage tool, but as a definitive diagnostic test.
They asked four experienced radiologists to re‑read 251 suspicious MRIs and classify each scan by how certain they were that significant cancer was present.
The radiologists were given three choices: “99% sure,” “90% sure,” or “less than 90% sure.”
What emerged was a strikingly clear pattern. In the “99% sure” group, MRI was perfect. In the “90% sure” group, it was nearly perfect. And below that threshold, certainty fell off sharply.
The authors describe the high‑certainty scans as having unmistakable features across all MRI sequences—T2, diffusion‑weighted imaging, and contrast enhancement—without the benign patterns or inflammatory changes that often confuse interpretation. “There is a group of patients in whom prostate cancer is close to certain based on MRI findings,” they write, emphasizing that this level of confidence was achieved even though most scans were performed on standard 1.5‑Tesla machines and had only average image quality.
The study’s conclusion is blunt: “This level of certainty… raises the possibility of omitting prostate biopsy before treatment in some patients.”
Kirkham and colleagues go further, suggesting that MRI alone may be as reliable as imaging used to diagnose kidney and testicular tumors—conditions where biopsy is often skipped entirely.
“The rate of false positives,” they note, “is well below what we accept in the kidney and testis.”
For men on Active Surveillance, the findings offer both reassurance and a glimpse of a gentler future. MRI has already become central to monitoring, but this study hints at a world where MRI might not just guide biopsies—it might replace them. The authors acknowledge that more work is needed, especially to ensure that radiologists with less experience can achieve similar accuracy. They also stress that this is a “hypothesis‑generating study,” not a call for immediate change in clinical practice.
Still, the direction is unmistakable. The team argues that the current PIRADS scoring system may not be suited for identifying lesions with near‑certain cancer.
“PIRADS 2.1 is probably unsuited to categorizing scans according to likelihood of tumor when high positive predictive values are required,” they write, noting that many of the “99% sure” tumors were small enough that PIRADS would have scored them only a 4, not a 5.
Their next step is to define the radiomic fingerprints of these “99% sure” lesions—those subtle combinations of shape, signal, and morphology that experienced radiologists recognize instantly—and to test whether those criteria can be taught, standardized, or even automated through machine learning.
For now, the message to patients is simple: MRI is getting better. Much better. And in the hands of experts, it may already be capable of diagnosing prostate cancer with near certainty.
As Kirkham’s team puts it, “We could be nearly certain of the presence of significant tumor in a considerable proportion of patients with suspicious MRI appearances.”
For men who have endured the biopsy needle, that sentence alone feels like a revolution.
By Howard Wolinsky, Editor, The Active Surveillor
Choosing Active Surveillance can be one of the biggest decisions a man makes after a prostate cancer diagnosis. But there can be another difficult question later on: How do you know when staying on Active Surveillance still makes sense — and when it may be time to consider treatment?
For Prostate Cancer Awareness Month, ASPI is bringing together three men on Active Surveillance, a urologist, and a pathologist to look at both sides of that question. We’ll talk about what patients and doctors consider when choosing Active Surveillance, what they watch during follow-up, and what kinds of changes may lead to a conversation about whether it is still the right approach.
Wayne Zimmermann and Joe Jones will share two different experiences of living with Active Surveillance — how they made the initial decision, what follow-up has been like, and how they deal with new information as it comes in. Mike Ondra will talk about mulling leaving AS.
Kevin Shee, MD, PhD, a urologist and Society of Urologic Oncology Fellow at UCSF, will talk about who may be a good candidate for Active Surveillance, what doctors look for during follow-up, and what kinds of changes may lead to a discussion about treatment.
Ming Zhou, MD, PhD, a urological pathologist at Mount Sinai, will help explain what doctors can learn from a prostate biopsy, what Gleason scores and Grade Groups mean, and why those findings matter when choosing or continuing Active Surveillance.
Saturday, September 26, 2026 • 12:00–1:30 PM Eastern Time
Patients are welcome to submit questions in advance to
contactus@aspatients.org.
There will also be time for live Q&A during the meeting.
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