PURPOSE: Magnetic resonance imaging (MRI) targeted prostate biopsy has been shown to find many high-grade prostate cancers in men with concurrent negative transrectal ultrasound (TRUS) systematic biopsy. The oncologic risk of such tumors can be explored by looking at long-term outcomes of men with negative TRUS-biopsy followed without MRI. The aim was to analyze the mortality after initial and second negative TRUS-biopsy.

MATERIALS AND METHODS: All men who underwent initial TRUS-biopsies between January 1, 1995 and December 31, 2016 in Denmark were included. A total of 37,214 men had a negative initial TRUS-biopsy and 6,389 underwent a re-biopsy. Risk of cause-specific mortality was analyzed with competing risks. Diagnosis of Gleason score ≥7 prostate cancer following negative biopsies was analyzed with multivariable logistic regression including time to re-biopsy, prostate specific antigen (PSA), age and digital rectal examination.

RESULTS: The 15-year prostate cancer-specific mortality was 1.9% (95% CI: 1.7-2.1). Prostate cancer-specific mortality was 1.3% (95% CI: 0.9-1.6) and 4.6% (95% CI: 3.4-5.8) for men with PSA <10 and >20 ng/ml, respectively. Of the TRUS re-biopsies 12% were Gleason score ≥7 and risk of Gleason score ≥7 increased with longer time to re-biopsy (p <0.001). Mortality after re-biopsy was similar to after initial biopsy.

CONCLUSIONS: Men with negative TRUS-biopsies have a very low prostate cancer-specific mortality, especially with PSA <10 ng/ml. This raises serious questions about the routine use of MRI targeting for initial prostate biopsy and suggests that MRI targeting should only be recommended for men with PSA >10 ng/ml after negative biopsy.