It has been questioned whether systematic transrectal ultrasound-guided biopsies (TRUS-gb) miss significant prostate cancers (PCa). MRI guided biopsies have been proposed for men where the initial TRUS-gb was normal and may increase sensitivity and detection of significant PCa, a definition based on the presence of a Gleason grade 4 or more in the biopsies. In 2010, Schröder et al. demonstrated with data from the ERSPC-study, that 0.03% of men with an initial, normal biopsy set died from PCa after 11 years of follow-up . Here, we calculate the risk of PCa specific mortality in men with an initial, benign biopsy set, in the complete nation-wide cohort of men who underwent evaluation for PCa with TRUS-gb during a 16-year period, in which systematic PSA screening or MRI was not part of the clinical setup.
Data originate from the Danish Prostate Cancer Register (DaPCaR). All men undergoing their first TRUS-gb in 1995-2011 were identified. Risk of PCa-specific mortality was analyzed in a competing risk setting treating death from non-PCa as competing risk.
64,430 men were referred for TRUS-gb. A total of 27,537 men had a benign first biopsy set, and 8,526 of these underwent a re-biopsy procedure. Median follow-up was 7.1 years. After 20 years, the estimated cumulative incidence of PCa mortality and other-cause mortality for all 64,430 included men was 25.6% and 50.5%, respectively. For men with an initial, benign TRUS-gb, the similar cumulative incidence of PCa mortality and other-cause mortality was 5.2% and 59.9% after 20 years, respectively. When stratified for level of PSA at time of referral, the estimated risk of PCa mortality after 15 years in men with a benign, first TRUS-gb was 0.7% for PSA ≤10 µg/L, 3.6% for PSA >10 20 µg/L.
Our data demonstrate, that the first systematic TRUS-gb does indeed diagnose patients at risk of PCa death. Our study supports the results from ERSPC, underlining that men with low PSA and an initial normal TRUS-gb rarely harbor lethal PCa. This information has implications for the future strategy of how to advise men with benign biopsies.
Clinical trial identification
Legal entity responsible for the study
The Danish Cancer Society, The Capital Region of Denmarks Fund for Health Research, Krista and Viggo Petersens Foundation
All authors have declared no conflicts of interest.