Prostate Health Index and Multiparametric MRI to Predict Prostate Cancer Grade Reclassification in Active Surveillance.

OBJECTIVE: To identify the value of combining the Prostate Health Index (PHI) and multiparametric magnetic resonance imaging (mpMRI), tools which have previously been shown to be independently predictive of prostate cancer (PCa) grade reclassification (GR) (Gleason score > 6), for the purpose of predicting GR at the next surveillance biopsy to reduce unnecessary prostate biopsies for men in PCa active surveillance (AS). PATIENTS AND METHODS: Between 2014 and 2019, we retrospectively identified 253 consecutive men in the Johns Hopkins AS program who had a mpMRI and PHI followed by a systematic +/- targeted biopsy. PHI and PHID were evaluated across PI-RADS version 2.0 (PI-RADSv2) scores and compared to those with and without GR. Next, the negative predictive value (NPV) and area under the receiver operating curve (AUC) were calculated to compare the diagnostic value of PI-RADSv2 score combined with PHI, PHID, or PSA density (PSAD) for GR using their respective 1st quartile as a cutoff. RESULTS: Of the 253 men, 38 men (15%) experienced GR. Men with GR had higher values of PHI (40.7 vs 32.0, p=0.001), PHID (0.83 vs 0.57, p=0.007) and PSAD (0.12 vs 0.10, p=0.037). PI-RADSv2 ≤3 alone had a NPV of 91.6% for GR (AUC 0.67). Using a PHI cut-off of 25.6 in addition to PI-RADSv2 ≤3, the NPV and AUC were both increased to 98% and 0.70, respectively. A PSAD cut-off of 0.07 ng/mL/cc with PI-RADSv2 had an AUC of 0.69 and NPV of 95.4%. PHI and PI-RADSv2 together could have avoided 20% of biopsies at the cost of missing 2.6% of GRs. CONCLUSIONS: The combination of PHI and mpMRI can aid in the prediction of GR in men on AS and may be useful for decreasing the burden of surveillance prostate biopsies.