Short noncontrast magnetic resonance imaging (MRI) may offer a better approach to population-based prostate cancer (PCa) screening compared with PSA testing alone or ultrasonography, recent study findings suggest.
Using a validated 5-point scale of suspicion, with higher scores indicating a greater likelihood of clinically significant cancer, investigators found that prostate MRI using a score of 4 or 5 to define a positive test result compared with PSA levels of 3 ng/mL or higher alone was associated with more men diagnosed with clinically significant PCa without increasing the number of men advised to undergo prostate biopsy or overdiagnosed with clinically insignificant cancer. The investigators found no evidence that ultrasonography would have performed better than PSA testing alone.
“The findings of this study indicated that an MRI score of 4 or 5 may provide a better balance between the potential benefits and harms of screening,” David Eldred-Evans, MBBS, of Imperial College London in London, UK, and colleagues wrote in JAMA Oncology.
The study included 408 men recruited at 7 primary care practices and 2 imaging centers in the United Kingdom and who consented to undergo screening with noncontrast biparametric MRI (with an acquisition time of approximately 15 minutes), ultrasonography, and PSA testing. The investigators considered an MRI or ultrasonography score of 3 to 5 and a PSA level of 3 ng/mL or higher to be positive test results. A systematic 12-core prostate biopsy was performed on men with a positive result on any test. The investigators defined clinically significant PCa as Gleason score 3+4 or higher disease.
The proportion of men with positive MRI results was significantly higher than the proportion with positive PSA test results (17.7% vs 9.9%). The proportion with positive ultrasonography results was also significantly higher than proportion of those with positive PSA test results (23.7% vs 9.9%).
Using a threshold score of 4 to 5, the proportion of men with positive MRI results (10.6%) was similar to the proportion with positive PSA test results (9.9%), as was the proportion with positive ultrasonography results (12.8%), Dr Eldred-Evans’ group reported.
Positive PSA test results detected 7 clinically significant cancers, whereas a positive result on MRI and ultrasonography (score 3 to 5) detected 14 and 9 clinically significant cancers, respectively. Using a score of 4 to 5 as the threshold for a positive result, MRI and ultrasonography detected 11 and 4 clinically significant cancers, respectively.
Positive PSA test results detected 6 clinically insignificant cancers (Gleason score 3+3). Positive MRI and ultrasonography results detected 7 and 13 clinically insignificant cancers, respectively, using a threshold score of 3 to 5, and 5 and 7 clinically insignificant cancers, respectively, using a threshold score of 4 to 5.
“These findings suggest that a short noncontrast MRI may have favorable performance characteristics as a community-based screening test,” the authors wrote.
In an accompanying editorial, Susanna I. Lee, MD, PhD, and Aileen O’Shea, MBBCh, of Massachusetts General Hospital and Harvard Medical School in Boston, Massachusetts, observed that the new findings “clearly point to prostate MRI as a promising screening test.”
Eldred-Evans D, Burak P, Connor MJ, et al. Population-based prostate cancer screening with magnetic resonance imaging or ultrasonography: The IP1-PROSTAGRAM study. Published online February 11, 2021. JAMA Oncol. doi:10.1001/jamaoncol.2020.7456
Lee SI, O’Shea A. Community-based screening for prostate cancer: A role for magnetic resonance imaging. Published online February 11, 2021. JAMA Oncol. doi:10.1001/jamaoncol.2020.7294