Incorporating MRI and biomarkers in active surveillance protocols - results from the prospective Stockholm3 Active Surveillance trial (STHLM3AS)
Mené en Suède sur 280 patients bénéficiant d'une surveillance active pour un cancer de la prostate à faible risque de récidive, cet essai multicentrique évalue la performance d'un protocole, combinant IRM et un système de score (basé sur 5 biomarqueurs plasmatiques, 101 variants constitutionnels et 5 variables cliniques), pour prédire le risque de reclassification de la tumeur et réduire la fréquence des biopsies
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.
Journal of the National Cancer Institute , article en libre accès, 2019