MRI-targeted or standard biopsy for prostate-cancer diagnosis

Background: The use of multiparametric MRI ± targeted biopsy (MRI±TB) is an alternative to standard transrectal ultrasound guided (TRUS) biopsy for prostate cancer detection in biopsy-naïve men with raised prostate specific antigen (PSA). However, comparative evidence is lacking.

Methods: PRECISION was a randomized, multicenter, non-inferiority trial, allocating 500 biopsy-naïve men with clinical suspicion of prostate cancer to MRI±TB or standard TRUS biopsy. Men randomized to MRI±TB had targeted biopsy (without standard biopsy cores) if the MRI was suspicious (PIRADSv2 score ≥3). Men with a non-suspicious MRI were not offered biopsy. Standard biopsy was a 10-12 core TRUS biopsy. The primary outcome was the proportion of men diagnosed with clinically significant cancer (Gleason grade ≥3+4). Planned secondary outcomes included the proportion of men diagnosed with clinically insignificant cancer (Gleason grade 3+3).

Results: Of the 252 men allocated to MRI±TB, 71 (28%) had a non-suspicious MRI and did not undergo biopsy. Clinically significant cancer was detected in 95 (38%) of 252 men in the MRI±TB arm compared to 64 (26%) of 248 men randomized to TRUS biopsy (adjusted difference, 11.7% [95% CI 3.6 to 19.8], P=0.005). MRI±TB was non-inferior to TRUS biopsy and the 95% CI indicated superiority of MRI±TB over TRUS biopsy. MRI±TB also diagnosed fewer men with insignificant cancer than TRUS biopsy (adjusted difference, -13.1% [95% CI -19.3 to -6.8, P<0.001]).

Conclusions: Pre-biopsy MRI risk assessment and MRI-targeted biopsy is superior to TRUS biopsy in biopsy-naïve men at clinical risk of prostate cancer.(Funded by the National Institute for Health Research (NIHR) and the European Association of Urology Research Foundation; Trial registration number: NCT02380027)