MRI Scans Can Avert Many Prostate Biopsies
In a large international trial, pre-biopsy MRI scans spared 28% of men from having to undergo a biopsy and resulted in a lower detection of clinically insignificant cancers vs standard biopsy.
Multiparametric magnetic resonance imaging (MRI) of the prostate prior to biopsy can safely decrease the number of unnecessary biopsies and increase the number of significant prostate tumors diagnosed compared with standard biopsy, according to the findings of an international randomized trial presented at the 33rd Annual European Association of Urology Congress in Copenhagen, Denmark, and published concurrently in the New England Journal of Medicine.
In the PRECISION trial, which enrolled 500 men with a clinical suspicion of prostate cancer (PCa) and no prior prostate biopsy, 71 (28%) of the 252 men randomly assigned to receive prostate MRI scans prior to biopsy did not undergo biopsy because their MRI results were not suggestive of PCa. Those who had MRI findings suggestive of cancer underwent a targeted biopsy based on MRI findings.
Clinically significant cancer, defined as the presence of a single biopsy core indicating Gleason score 3+4 disease or greater, was detected in 95 men (38%) who underwent pre-biopsy MRI followed by MRI-targeted biopsy compared with 64 (26%) of 248 men who underwent standard transrectal ultrasonography (TRUS)-guided 10–12 core biopsy. A significantly smaller proportion of men in the MRI group compared with the standard-biopsy group received a diagnosis of clinically insignificant cancer (9% vs 22%).
In addition, among men who underwent further biopsy, clinical significant cancer was detected in none of the 4 men in the MRI-targeted biopsy group and in 3 (33%) of men in the standard-biopsy group. Of the 71 men with negative results on MRI and no biopsy, 3 (4%) were discharged, 62 (87%) were referred for monitoring of PSA levels, and 3 (4%) underwent further biopsy and had negative results, the investigators reported. One patient (1%) had an additional multiparametric MRI and 2 (3%) had missing information.
“The ideal test for prostate cancer would be minimally invasive, have few side effects, identify a high proportion of men who would benefit from treatment, and minimize the identification of men with clinically insignificant cancer in order to prevent overtreatment,” Veeru Kasivisvanathan, MRCS, of University College London (UCL) and UCL Hospitals NHS Foundation, and colleagues wrote in their journal report. “In men with a clinical suspicion of prostate cancer who had not undergone biopsy of the prostate previously, the PRECISION trial showed that MRI, with or with or without targeted biopsy, appeared to achieve these goals better than the traditional standard of care, transrectal ultrasonography-guided biopsy.”
In a news release issued by the EAU, Hein Van Poppel, MD, PhD, of University Hospitals of the Leuven in Belgium, who was not involved the trial, commented, “This work shows that using MRI to decide whether or not to perform a biopsy has the potential to save around a quarter of a million European men each year from going through the biopsy procedure, and so may be cost-effective in the long run. … We need time to digest the study, but at first reading, it looks like it has the potential to change clinical practice.”
In the same release, the study's senior author, Caroline M. Moore, FRCS (Urol), of UCL, observed, “The MRI pathway detected more harmful cancers that needed treatment, and it reduced overdiagnosis of harmless cancers, even though fewer men had a biopsy in the MRI arm.”
Kasivisvanathan V, Rannikko AS, Borghi M, et al. MRI-targeted or standard biopsy for prostate-cancer diagnosis. N Engl J Med. 2018; published online ahead of print. DOI: 10.1056/NEJMoa1801993.