“Journal Article of the Month” is a new Urology Times section in which Badar M. Mian, MD (left), offers perspective on noteworthy research in the peer-reviewed literature. Dr. Mian is associate professor of surgery in the division of urology at Albany Medical College, Albany, NY.
In men with clinical suspicion of prostate cancer (elevated PSA or abnormal DRE), multiparametric magnetic resonance imaging of the prostate may be useful as a triage test to reduce the number of unnecessary biopsies while enhancing the detection of clinically significant prostate cancer (CS-PCa). The recent paper from the PRECISION study group reported that, in biopsy-naïve men, CS-PCa detection (any core with Gleason score ≥3+4) was significantly higher and the risk of cancer detection was significantly lower in men undergoing MRI-targeted biopsy when compared to the standard transrectal ultrasound-guided biopsy (N Engl J Med March 18, 2018 [Epub ahead of print]).
The authors identified 500 patients with elevated PSA and/or abnormal DRE and randomized 252 men to the MRI-targeted biopsy group and 248 to the standard-biopsy group. Of the 252 men in the MRI-targeted biopsy group, 181 (72%) with suspicious lesions (defined as PIRADS 3-5) underwent biopsy of the target lesions only while 71 men (28%) with a normal MRI (PIRADS 1 or 2) did not undergo a biopsy at all. While the standard-biopsy group had systematic biopsy with an average of 12 cores, the MRI targeted biopsy obtained an average of four cores per patient.
Ninety-five men (38%) in the MRI-targeted biopsy group had CS-PCa compared to 64 (26%) in the standard-biopsy group (p=.005). Fewer men were diagnosed with low-risk prostate cancer in the MRI-targeted biopsy group (23 men, 9%) than in the standard-biopsy group (55 men, 22%, p<.001).
In men with the MRI demonstrating a targetable lesion, 51 of 175 (29%) had a PI-RADS score 3, 70 (40%) had a score of 4, and 54 (31%) had a score of 5. CS-PCa rate for PIRADS score 3, 4, and 5 was 12%, 60%, and 83%, respectively. Conversely, the negative biopsy rate for PIRADS score 3, 4, and 5 was 67%, 31%, and 6%, respectively.
Percentage of biopsy cores with cancer was significantly higher in the MRI-targeted biopsy group (422 of 967 cores, 44%) than in the standard-biopsy group (515 of 2,788 cores, 18%); ie, much fewer cores were needed to detect a higher rate of CS-PCa. Post-biopsy complications were less common in the MRI-targeted group than the standard-biopsy group, including hematuria (30% vs. 63%), hematospermia (32% vs. 60%), pain (13% vs. 23%), rectal bleeding (14% vs. 22%), and erectile dysfunction (11% vs. 16%), respectively. This difference in the patient-reported 30-day complication rate is explained by the fact that fewer men in the MRI-targeted group needed a biopsy and only a few cores were obtained per biopsy session.