Background
Active surveillance (AS) for men with low-risk prostate cancer (PC) can lead to patient morbidity and healthcare overutilization. The aim of this study was to evaluate an AS-protocol using the Stockholm3 test and MRI to reduce biopsy intensity.
Methods
We conducted a prospective multicenter study of 280 invited men from a contemporary screening study (STHLM3), with Gleason Score (GS) 3 + 3 PC on a current AS-protocol. Patients underwent prostate-MRI and blood sampling for analysis of the Stockholm3 test including protein biomarkers, genetic variants and clinical variables to predict risk of GS ≥ 3 + 4 PC, then followed by systematic biopsies and targeted biopsies (for PIRADS ≥3 lesions) in all men. Primary outcomes were reclassification to GS ≥ 3 + 4 PC and clinically significant PC (csPC) including unfavorable intermediate risk PC or higher based on NCCN-guidelines.
Results
Adding MRI-targeted biopsies to systematic biopsies increased sensitivity of GS ≥ 3 + 4 PC compared to systematic biopsies alone (relative sensitivity (RS) = 1.52; 95% CI = 1.28 to 1.85). Performing biopsies in only MRI positive increased sensitivity of GS ≥ 3 + 4 PC (RS = 1.30; 95% CI = 1.04 to 1.67), reduced number of biopsy procedures by 49.3% while missing 7.2% GS ≥ 3 + 4 PC and 1.4% csPCa. Excluding men with negative Stockholm3 test reduced number of MRI investigations at follow-up by 22.5%, biopsies by 56.8% while missing 6.9% GS ≥ 3 + 4 PC and 1.3% csPCa.
Conclusion
During AS, including MRI and targeted/systematic biopsies increase sensitivity of PC reclassification. Incorporation of risk prediction models including biomarkers may reduce the need for MRI use in men with low risk PC.
