MRI-based approach noninferior to standard biopsy for prostate cancer detection
medwireNews: In men at clinical risk for prostate cancer, a strategy involving multiparametric magnetic resonance imaging (MRI) risk assessment followed by targeted biopsy is noninferior, and may even be superior, to standard transrectal ultrasonography (TRUS)-guided biopsy, say the PRECISION researchers.
The PRECISION (Prostate Evaluation for Clinically Important Disease: Sampling Using Image Guidance or Not?) trial enrolled 500 men with an elevated prostate-specific antigen level (but no higher than 20 ng/mL), abnormal digital rectal exam, or both, who had not previously undergone a biopsy.
Clinically significant cancer – defined as disease of Gleason score 3+4 or greater – was detected in 38% of participants who were randomly assigned to undergo an MRI-targeted biopsy and 26% of their counterparts who had a standard 10–12-core, TRUS-guided biopsy. This gave a difference of 12 percentage points, where the lower limit of the confidence interval met the criteria for noninferiority and also indicated superiority of the MRI-based strategy.
Of note, participants in the MRI arm only underwent a biopsy if the initial multiparametric MRI was suggestive of prostate cancer, and, as such, 28% of men in the group were able to avoid a biopsy altogether.
Furthermore, clinically insignificant cancers were detected significantly less frequently in the MRI versus the standard biopsy group, with corresponding rates of 9% and 22%, and the rate of subsequent diagnostic tests was also lower, at 3% compared with 16% in the standard biopsy arm.
“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,” say the PRECISION investigators, adding that the MRI-based strategy seemed to achieve these goals better than the standard approach.
Veeru Kasivisvanathan, from University College London in the UK, and co-authors write in The New England Journal of Medicine: “We acknowledge that a change in the standard of care for prostate-cancer diagnosis would entail changes in health care systems to accommodate appropriate MRI capacity and to meet the training needs of radiologists and urologists.
“From a health economics perspective, the cost savings with MRI, with or without targeted biopsy, over standard [TRUS]–guided biopsy may emerge from the earlier detection of clinically significant cancers, fewer cases of insignificant cancer diagnosed, and fewer repeat biopsies.”
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