Optimizing detection of clinically significant prostate cancer through nomograms incorporating mri, clinical features, and advanced serum biomarkers in biopsy naïve men.

PURPOSE: To develop nomograms that predict the detection of clinically significant prostate cancer (csPCa, defined as ≥GG2 [Grade Group 2]) at diagnostic biopsy based on multiparametric prostate MRI (mpMRI), serum biomarkers, and patient clinicodemographic features. MATERIALS AND METHODS: Nomograms were developed from a cohort of biopsy-naïve men presenting to our 11-hospital system with prostate specific antigen (PSA) of 2-20 ng/mL who underwent pre-biopsy mpMRI from March 2018-June 2021 (n = 1494). The outcomes were the presence of csPCa and high-grade prostate cancer (defined as ≥GG3 prostate cancer). Using significant variables on multivariable logistic regression, individual nomograms were developed for men with total PSA, % free PSA, or prostate health index (PHI) when available. The nomograms were both internally validated and evaluated in an independent cohort of 366 men presenting to our hospital system from July 2021-February 2022. RESULTS: 1031 of 1494 men (69%) underwent biopsy after initial evaluation with mpMRI, 493 (47.8%) of whom were found to have ≥GG2 PCa, and 271 (26.3%) were found to have ≥GG3 PCa. Age, race, highest PIRADS score, prostate health index when available, % free PSA when available, and PSA density were significant predictors of ≥GG2 and ≥GG3 PCa on multivariable analysis and were used for nomogram generation. Accuracy of nomograms in both the training cohort and independent cohort were high, with areas under the curves (AUC) of ≥0.885 in the training cohort and ≥0.896 in the independent validation cohort. In our independent validation cohort, our model for ≥GG2 prostate cancer with PHI saved 39.1% of biopsies (143/366) while only missing 0.8% of csPCa (1/124) with a biopsy threshold of 20% probability of csPCa. CONCLUSIONS: Here we developed nomograms combining serum testing and mpMRI to help clinicians risk stratify patients with elevated PSA of 2-20 ng/mL who are being considered for biopsy. Our nomograms are available at https://rossnm1.shinyapps.io/MynMRIskCalculator/ to aid with biopsy decisions.

Real-world use of MRI for risk stratification prior to prostate biopsy.

BACKGROUND: The utilization of MRI to risk stratify elevated PSA prior to prostate biopsy has been inconsistently adopted and varies considerably by practice setting. This study aims to evaluate the usage and performance of MRI as an advanced risk stratification tool of elevated PSA prior to biopsy and identify factors associated with differential utilization of MRI at a large academic setting with ready access to 3T multiparametric MRI of the prostate. METHODS: A retrospective single-center study of 2900 men presenting with elevated PSA 2-20 ng/mL from 2018 through 2021 was conducted. We analyzed trends in MRI utilization and outcomes of prostate biopsy by MRI usage. Univariate and multivariate logistic regressions were performed to calculate odds ratios to identify patient- and provider-level predictors of MRI usage. RESULTS: Rates of prebiopsy MRI utilization increased from 56% in 2018 to 89% in 2021 (p < 0.001). Prebiopsy MRI led to biopsy avoidance in 31% of men. MRI usage enhanced detection of clinically significant prostate cancer by 13% and reduced identification of Gleason Grade Group 1 disease by 3% and negative biopsies by 10% (p < 0.001). Men who received MRI were more likely to be younger than 75 years in age and have private or Medicare insurance, PSA >4 ng/mL, and PHI >27. In both univariate and multivariate analysis, black race and Medicaid insurance were associated with reduced MRI utilization (all p < 0.001). Urologic provider was an independent predictor of MRI usage (p < 0.001). CONCLUSIONS: Use of MRI as a risk stratification tool for elevated PSA rose during this 4-year study period. Men who self-identify as black or men with Medicaid coverage have diminished rates of MRI usage. Considerable provider-level variability in MRI use was observed. Future research aimed at identifying factors affecting implementation of MRI as a routine risk assessment tool is warranted.