The value of a first MRI and targeted biopsies after several years of active surveillance for low-risk prostate cancer–results from the SAMS trial

Abstract

Objective: To assess the value of a first MRI examination and image-fusion-guided biopsies in men with low-risk prostate cancer who have been on active surveillance (AS) for several years with no signs of progression. Patients and Methods: All 45 participants from two centers who had not previously had an MRI were included. They had been on AS for T1c Gleason score 6 prostate cancer for 2.6 to 6.7 years and had 2 to 5 sets of systematic biopsies with a total of 1640 cores. All underwent a bi-parametric MRI, PI-RADS ≥ 3 lesions were targeted with image-fusion-guided biopsies. Primary outcome measure: detection of Gleason score ≥7 cancer. Results: Twenty-five of the 45 men (56%) had a total of 30 suspicious MRI lesions. The lesion with the highest score was a PI-RADS 3 in 18, a PI-RADS 4 in 5 and PI-RADS 5 in 3 men. Targeted biopsies from the 30 lesions detected Gleason score 7 cancer in 6 men. Of these six cancers, four were located in the apical and one in the anterior/apical part of the prostate. A Gleason score 7 cancer was detected in 3 of 5 men with PSA density >0.15 ng/ml/cm3. Conclusions: Even after several years of AS with stable PSA values and many sets of systematic biopsies, a first MRI and targeted biopsies lead to the detection of Gleason score 7 (ISUP 2 and ISUP 3) cancer in a significant proportion of men, particularly among those with a high PSA density.