Adding MRI to Screening Can Cut Prostate Cancer Overdiagnosis in Half
One of the big issues in prostate cancer care is overdiagnosis -- men who are treated for low-risk, slow-growing tumors that might be better left monitored and untreated.
Now, research out of Sweden suggests that having patients undergo MRI screening, along with targeted biopsies, could reduce the number of prostate cancer overdiagnoses by half.
The new approach can detect just as many clinically significant tumors as current methods, but reduces unnecessary biopsies and the identification of minor low-risk tumors, according to the study presented July 9 at the European Association of Urology Congress. The findings were published simultaneously in the New England Journal of Medicine.
The findings show that "modern methods for prostate cancer screening maintain the benefits of screening, while decreasing the harms substantially," said study co-leader Tobias Nordström. He is associate professor of urology at Danderyd Hospital at the Karolinska Institute.
"This addresses the greatest barrier to the introduction of nationwide screening," Nordström explained in an institute news release.
One expert in the United States said the research holds real promise.
"For the past 20 years, urologists and researchers have been striving to improve prostate cancer screening to target men with clinically significant prostate cancer and avoid overdiagnosis in men with low-risk prostate cancer," said Dr. Manish Vira, system chief of urology at Northwell Health Cancer Institute in New Hyde Park, N.Y.
The Swedish findings show how the use of highly targeted MRI "has moved our field closer to the goal," said Vira, who wasn't involved in the new study.
As the Stockholm team explained, most countries no longer have nationwide prostate-cancer screening programs in place because current methods -- PSA (prostate-specific antigen) blood testing plus traditional biopsies -- often result in overdiagnosis and unnecessary biopsies, meaning the risks of screening can outweigh the benefits.
In too many cases, so-called "indolent" prostate tumors grow at such a slow pace that treating them brings harms (such as urinary issues and impotence) that exceed any real risk from the tumor to the patient's health.
But is there a better way to spot those higher-risk tumors that do need treatment?
In the new study, the Karolinska team tracked outcomes for 12,750 Swedish men between 2018 and 2021. Blood samples were collected from the men for PSA analysis, as well as analysis by the new Stockholm3 test, developed by institute researchers.
Men whose tests revealed elevated PSA levels were then randomly selected to undergo either traditional biopsies or they underwent MRI.
In the MRI group, biopsies were conducted only on suspected tumors identified by MRI.
The new approach can detect just as many clinically significant tumors as current methods, the researchers said, but it reduces unnecessary biopsies and the identification of minor low-risk tumors.
Vira explained that "by incorporating MRI into the prostate cancer screening process, we can better recommend biopsy in those men who are at high risk, and perhaps just as importantly, avoid unnecessary biopsies in men who don't have prostate cancer or have indolent/insignificant disease."
Dr. Art R. Rastinehad is associate professor of urology and radiology and vice chair of urology at Lenox Hill Hospital in New York City. He wasn't involved in the Swedish research, but called it "another great study supporting the use of MRI before a prostate biopsy in men at risk of prostate cancer."
He pointed out that "prostate cancer was the last solid organ malignancy that was diagnosed without imaging, so we are very excited to continue to use advanced imaging technologies to help our patients."
The potential benefits to patients are clear, he added.
"It is estimated that up to 51% of patients having their prostate removed may be candidates for a less invasive, outpatient treatment that helps them get back to their normal lives with a lower risk of urinary incontinence and/or erectile dysfunction," Rastinehad said.
The U.S. National Cancer Institute has more on prostate cancer screening.
SOURCES: Art R. Rastinehad, DO, associate professor of urology and radiology, vice chair of urology, Lenox Hill Hospital, New York City; Manish A. Vira, MD, system chief of urology, Northwell Health Cancer Institute, New Hyde Park, N.Y.; Karolinska Institute, news release, July 9, 2021