In a prostate cancer screening program, is it possible to safely reduce the detection of clinically insignificant prostate cancers by only performing a biopsy of the most suspicious lesions seen on magnetic resonance imaging?
A strategy of only performing biopsies on lesions deemed suspicious on MRI, without systematic ("random") biopsies appears to safely find the more important cancers while reducing the total number of biopsies and potentially the need for active treatment or active surveillance.
Plan de l'etude:
Randomized controlled trial (nonblinded)
An important harm of prostate cancer screening using prostate specific antigen (PSA) is the detection of prostate cancers that are unlikely to cause harm, but still result in either active surveillance or active treatment with surgery or radiation. In this study, 37,887 men, aged 50 to 60 years, were invited for screening by PSA, and slightly less than half accepted (N = 17,980). All the patients with a PSA greater than 3.0 ng/mL underwent magnetic resonance imaging (MRI) of the prostate. One-third of the men were randomized into the reference group and underwent 10 to 12 systematic biopsies of the prostate, as well as targeted biopsy of any suspicious lesion seen on MRI (PI-RADS grade 3 to 5). Another third of the men were randomized into the experimental groups and only underwent targeted biopsies if their PSA was greater than 3.0 ng/mL, unless the PSA was greater than 10 ng/mL in which case they also underwent systematic biopsies. If those patients had a low-grade prostate cancer (largely Gleason score 3+3), they were also invited back for systematic biopsy to avoid sampling bias. (The remaining third of the men underwent MRI if their PSA was greater than 1.8 ng/mL, but their results are not reported here.) The groups were balanced, and analysis was by intention to treat. A clinically insignificant prostate cancer was defined as a Gleason score of 3+3 and was detected less often in the experimental group, which is a good thing (0.6% vs 1.2%; P < .001). A clinically significant cancer (Gleason 3+4 or higher) was detected to a similar extent in the 2 groups, also a good thing (0.9% experimental and 1.1% reference; relative risk = 0.81; 95% CI 0.60 - 1.10). Of the clinically significant cancers detected in the reference group, only 10 of 68 were detected by the systematic biopsies, of which 3 were treated surgically and 1 with radiation.
Mark H. Ebell, MD, MS
University of Georgia