Does mpMRI improve clinical criteria in selecting men with prostate cancer for active surveillance?

BACKGROUND: Active surveillance (AS) has excellent short to medium term outcomes in well-selected prostate cancer patients. Traditional biopsy-based selection criteria have been criticized for inaccurate determination of cancer grade and extent. We evaluated the incremental benefit of multiparametric magnetic resonance imaging (mpMRI) in patient selection using various AS criteria.

METHODS: We retrospectively evaluated men who received mpMRI before radical prostatectomy between 2011 and 2014. Patients were classified as suitable for AS using four criteria: (1) Epstein, (2) National Comprehensive Cancer Network (NCCN) low-risk or (3) extended criteria (Gleason ⩽3+4, PSA ⩽15 ng/ml, clinical stage ⩽T2b) using clinical parameters. The incremental value of mpMRI was evaluated against the referent standard of surgical pathology in determining suitability for AS using sensitivity, specificity, likelihood ratios (LRs) and area under receiver operating curves (AUCs).

RESULTS: We evaluated 208 men. Only one man fulfilled Epstein criteria (1) at pathology, who was neither identified using clinical criteria nor mpMRI. Using (2), clinical criteria had a sensitivity of 80%, specificity 75%, LR+ 3.3, LR- 0.3, AUC 0.78, while combined clinical-mpMRI criteria achieved a sensitivity of 80%, specificity 99.5% (P<0.01), LR+ 162, LR- 0.2 and AUC 0.90 (P<0.01 compared to clinical). Using (3), clinical criteria had a sensitivity of 74%, specificity 47%, LR+ 1.4, LR- 0.6, AUC 0.60, while combined clinical-mpMRI criteria achieved a sensitivity of 26% (P<0.01), specificity 97% (P<0.01), LR+ 8.3, LR- 0.8 and AUC 0.62 (P=0.85).

CONCLUSIONS: Addition of mpMRI significantly improved selection of men for AS using NCCN low-risk criteria. For selecting men with limited prognostic grade group 2, mpMRI significantly improved specificity at the expense of sensitivity.