Prebiopsy MRI study offers strong reassurance that patients can safely skip risky biopsies, German researchers report

(Editor’s note: This just-published German study should offer reassurance to patients with Grade Group (Gleason 2) and above who have received a negative biopsy. Part II on MRI coming.)

By Howard Wolinsky

Evidence is mounting that prebiopsy multi-parametric magnetic resonance imaging (MRI) not only find most significant prostate cancers but also can spare many men with rising PSAs from unnecessary biopsies.

A new German study of 593 men, aged 58-70 published in JAMA Oncology on Dec. 12 showed that men with negative MRI results may not be at an elevated risk for clinically significant prostate cancer (Grade Group 2, Gleason 3+4,and above). (Those of us with Grade Group 1 are not considered to have clinically significant cancer.)

Charlie Hamm, MD, PhD, of the Department of Radiology, Charité–Universitätsmedizin Berlin, and his colleagues concluded that men with negative MRIs can safely avoid biopsy when appropriate monitoring (surveillance) measures are implemented.

(Dr. Charlie Hamm)

Adam B. Weiner, MD, a urologic oncologist in the Department of Urology at Samuel Oschin Comprehensive Cancer Institute at Cedars-Sinai Medical Center in Los Angeles, said this study, unlike earlier ones, provides follow-up on patients with negative MRIs. “This is really critical and part of the reason why this new study is so important. This study shows is that if patients have a negative MRI with a high suspicion for prostate cancer now or in the near future, they can be monitored closely with MRI, PSA, and subsequent biopsies. The latest study showed there were very few patients with significant prostate cancer within a couple years after a negative MRI.

“It’s also important to know that the natural history of prostate cancer can be quite long. This means that, even if you miss a significant prostate cancer for a few years, the chances that this lowers, the patient’s chance for cure prolonged remission with treatment is low.”

(Dr. Adam Weiner)

The findings were impressive:

—48% of patients had negative MRI results.

— Of those, 86% avoided biopsy over 3 years.

—After 3 years of programmatic monitoring, clinically significant prostate cancer was detected in 4% of men with negative MRI results who exhibited an ongoing elevated clinical risk.

“Reducing the number of prostate biopsies certainly results in a lower number of detected[clinically insignificant prostate cancer] and subsequent overtreatment, as potentially missed MRI-invisible cancers are mainly insignificant (GG 1) or low-volume localized GG 2 PCa,” Hamm et al. wrote

Weiner, a spokesman for the American Urological Association, said of the German study: “MRI had a negative predictive value of 96%. This means that if a patient has a negative MRI, there is a 96% chance they do not have a significant prostate cancer. This should be incredibly reassuring to patients.”

The Germans said: “The strong adherence of patients and urologists to the active monitoring approach (safety net strategy), which is in line with current UK safety net guidelines for the follow-up of men with negative MRI results (guidelines that did not exist at the initiation of the trial), coupled with the reduced biopsy rate, proves both the applicability and safety of the MRI pathway in common clinical practice.”

Evidence is building in favor of prebiopy MRIs.

Weiner cited another study in April in JAMA Oncology that reviewed 12 earlier publications looking at prostate MRIs and biopsies. “They showed that using MRI along with PSA prior to biopsy helps to decrease the number of biopsies needed, decrease the number of clinically insignificant prostate cancer detected, and increase the number of clinically significant prostate cancer detected.”

A large Swedish study appearing in New England Journal of Medicine this year found advantages to prebiopy MRI.

Patients were randomized over three years to prostate cancer screening with and without MRI prior to biopsy. The rate detection of clinically insignificant process cancer was cut in half in those patients who went to an MRI. And there was no difference in the detection of clinically significant prostate cancer.

The Active Surveillor columnist Antonio Westphalen, MD, a top radiologist at University of Washington, reviewed the Swedish study here.

Are there downsides to MRI first?

“Downsides include cost of the MRIs and the time it takes to get them. In some busy centers, it could take weeks to months to get one for patient. Some insurances might not pay the total cost still despite the guidelines. Additionally, prostate MRI’s typically take about 45 minutes which is difficult for some patients with claustrophobia,” Weiner said.

Final word from Weiner: “Avoiding biopsies is one crucial step to help producing a healthcare cost and harm to patients.”

Tick-tock. Do you want to attend the Jan. 4 AS year-in-review webinar, featuring four top prostate experts. You need a paid subscription, If you feel you can’t afford one, please contact me at Howard.wolinsky@gmail.com. I know a guy who can get you in.

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