PIRADS-3 lesions and clinically significant prostate cancer – what are we missing?
Reviewed by Karthik Rajan

The use of pre-biopsy MRI has definitely enhanced our decision making in managing patients with suspected prostate cancer (PCa). There is still uncertainty around the outcomes for patients with PIRADS-3 lesions, with a small but definite risk of missing clinically significant cancer (csPCa). The authors attempt to identify the pathology of these lesions and identify predictors of csPCa. They included 150 patients between January 2014 and January 2020 who had PIRADS-3 only on MRI, underwent both systematic (SB129) and targeted (TB) biopsies followed by radical prostatectomy (RP). TB was done using elastic fusion (KOELIS® system). They defined csPCa as Grade Group 2 or more. The primary endpoints were unfavourable outcomes – Grade Group 3-5, pT3-4 stage or both and upgrading rates. The median prostate specific antigen (PSA) level was 8.0ng/mL (5.8-12). 33.3% of patients had a previous negative biopsy. Biopsy Grade Group was 1, 2, 3 and 4–5 in 28.7%, 52.7%, 16.0% and 2.6%, respectively with final Grade Group after RP being 1, 2, 3 and 4–5 in 8.7%, 54.7%, 30.0% and 6.7%, respectively. The upgrading rates were 54.4% for SB, 47.9% for TB and 38.2% for SB+TB. The final histology was concordant with SB in only 38.2% of cases. Multivariate analysis showed PSAD (P=0.001) and presence of csPCa on TB (p=0.001) were independent predictors of unfavourable disease. The risk was 2.3-fold and 5.8-fold for PSAD of 0.15-0.20 and >0.20ng/mL/g, respectively. For csPCa on TB the risk increased by 3.7-fold. Pre-biopsy MRI with SB and TB is the established standard of care for diagnosis of PCa. This study shows that there is a good percentage of patients who would have a missed csPCa using only MRI and biopsy findings. Although addressing variability in reporting of MRI and Gleason grade would reduce this risk, it is necessary to identify other parameters to help preoperative risk assessment.

Pathological features of Prostate Imaging Reporting and Data System (PI-RADS) 3 MRI lesions in biopsy and radical prostatectomy specimens.
Rahota R-G, Diamand R, Malavaud B, et al.
BJU INTERNATIONAL
2022;129:621-6.