[Pathology findings after radical prostatectomy for prostate cancer in patients eligible for active surveillance: Contribution of multiparametric MRI to treatment decision]

Objectives: To analyze, in patients with prostate cancer (PC) potentially eligible for active surveillance (AS), whether multiparametric-MRI (mp-MRI) predicts presence of clinically significant cancer on radical prostatectomy (RP) specimen.

Methods: We identified 77 men with PC eligible for AS (PSA≤15ng/mL, stage≤T2a, Gleason score≤6, up to 3 positive cores, maximal cancer core length≤5mm) who underwent RP between 01/2008 and 08/2015. All patients had prebiopsy mp-MRI followed by systematic±targeted biopsies. For each patient, the likelihood of the presence of cancer on mp-MRI was assigned using Likert scale (1 to 5). The predictive factors for the presence of significant cancer on RP specimen (Gleason score≥7 and/or tumoral maximal diameter>10mm) were evaluated using logistic regression.

Results: Median age was 61 and median PSA was 6.7ng/mL. Overall, 49 (64%) patients had a positive mp-MRI (score≥3). Clinically significant cancer on RP specimen was found in 45 (58%) patients (69% in MRI-positive patients vs 39% in MRI-negative patients). In multivariate analysis, a positive MRI was a predictive factor for the presence of significant cancer on the surgical specimen (OR=3.0; CI95% [1.01-8.88]; P=0.04), as was age (OR=1.17; CI95% [1.05-1.31]; P=0.004) and PSAD (OR=1.10; CI95% [1.01-1.20]; P=0.02).

Conclusion: Mp-MRI is a useful exam for selecting patients eligible for AS even if the situation remains unclear after prostate biopsies including targeted biopsies. Upon confirmation by further studies, mp-MRI should be considered as an independent criterion before entering an AS program.

Level of evidence: 4.