Combined MRI, US-guided biopsy detects more prostate cancers

Biopsy guided by ultrasound (US) is the traditional method to determine if men have prostate cancer. But a new study found adding MRI-guided biopsy can increase the rate of prostate cancer detection.

Results of the Prospective Assessment of Image Registration in the Diagnosis of Prostate Cancer (PAIREDCAP) study, published June 12, in JAMA Surgery compared both US and MRI sampling methods. They found a combined strategy detected up to 33% more cancers than standard methods alone.

“Our research suggests that the different biopsy methods identify different tumors,” senior author Leonard Marks, MD, chair in the department of urology at UCLA’s David Geffen School of Medicine in Los Angeles, said in a prepared statement. “To maximize our ability to identify prostate cancer, we need to take advantage of all the information we can. Our cancer detection rate, while using different methods in tandem, surpasses that from using either method alone. In this case, one plus one equals three.”

MRI allows clinicians to visualize specific lesions in the prostate and only take tissue samples from those spots, but combining US with MRI is rarely done, according to Marks.

The PAIREDCAP study enrolled 300 men undergoing first-time prostate biopsy between January 2015 and April 2018. Of that total, 248 had a prostate lesion visible on MRI while the remaining 52 were control patients. The primary endpoint was the detection of clinically significant prostate cancer overall and by each biopsy method separately. Secondary end points were the effects of the Prostate Imaging Reporting & Data System (PI-RADS) version 2 grade, prostate-specific antigen (PSA) density and prostate volume on the primary endpoint.

In those in the combined biopsy group, the overall cancer detection rate was 70%. In 15% of the control group with no visible lesions on MRI, traditional US detected the presence of cancer, affirming different biopsy methods do in fact identify different cancers.

For all biopsy methods the PI-RADS and PSA density were directly associated with cancer detection rates, while prostate volume was inversely associated, the authors noted.

“Men being assessed for prostate cancer should first receive an MRI before biopsy,” Marks said in the same release. “When there’s a lesion on MRI, physicians should take systematic and targeted biopsies together for the best chance at finding cancer. Even if the MRI is negative for lesions, men at risk—including those with elevated levels of prostate-specific antigen, a prostate nodule, or family history—should still receive a traditional, systematic biopsy.”