Cumulative cancer locations on prostate biopsy and active surveillance outcomes in the MRI era.

BACKGROUND: To validate the use of a cumulative cancer locations (CCLO) score, a measurement of tumor volume on biopsy, and to develop a novel magnetic resonance imaging (MRI)-informed CCLO (mCCLO) score to predict clinical outcomes on active surveillance (AS). METHODS: The CCLO score is a sum of uniquely involved sextants with prostate cancer on diagnostic + confirmatory biopsy. The mCCLO score incorporates MRI findings into the CCLO score. Participants included 1284 individuals enrolled on AS between 1994 and 2022, 343 of whom underwent prostate MRI. The primary outcome was grade reclassification (GR) to grade group ≥2 disease; the secondary outcome was receipt of definitive treatment. RESULTS: Increasing CCLO and mCCLO risk groups were associated with higher risk of GR and undergoing definitive treatment (both p < 0.001). On multivariable analysis, increasing mCCLO score was associated with higher risk of GR and receipt of definitive treatment (hazard ratios [HRs] per 1-unit increase: 1.26 [95% confidence interval [CI]: 1.12-1.41] and 1.21 [95% CI: 1.07-1.36], respectively). The model using mCCLO score to predict GR (c-index: 0.671; 95% CI: 0.621-0.721) performed at least as well as models using the number of cores positive for cancer (0.664 [0.613-0.715]; p = 0.7) and the maximum percentage of cancer in a core (0.641 [0.585-0.696]; p = 0.14). CONCLUSIONS: The CCLO score is a valid, objective metric to predict GR and receipt of treatment in a large AS cohort. The ability of the MRI-informed mCCLO to predict GR is on par with traditional metrics of tumor volume but is more descriptive and may benefit from greater reproducibility. The mCCLO score can be implemented as a shorthand, informative tool for counseling patients about whether to remain on AS.

Baseline prostate health index risk category and risk category changes during active surveillance predict grade reclassification.

BACKGROUND: It is not known whether baseline prostate health index (PHI) at the initiation of active surveillance (AS) or repeated PHI testing during AS is of clinical value after confirmatory biopsy in AS men followed with multiparametric magnetic resonance imaging (mpMRI). METHODS: We identified 382 AS patients with no greater than Grade Group 1 (GG1) prostate cancer on diagnostic and confirmatory biopsy, at least one mpMRI and PHI test, of which 241 had at least 2 PHI tests. Grade reclassification (GR) was defined as ≥GG2 on surveillance biopsy. PHI risk categories 1 to 4 were as defined by the manufacturer. Associations between baseline PHI risk category or baseline PSA density (PSAD), change in PHI risk categories over time or PSAD changes over time and GR were evaluated with multivariable Cox proportional hazard regression models adjusted for age, Prostate Imaging-Reporting and Data System score and number of positive cores. RESULTS: Men with baseline PHI scores in the highest risk categories had lower rates of GR-free survival (log-rank P < 0.001), as did those who increased in PHI risk category or remained in a high PHI risk category during surveillance (log-rank P = 0.032). On multivariable regression, baseline PHI risk category was a predictor of GR (risk category 4 [vs. 1] hazard ratio [HR] 2.74, 95% confidence interval [CI] 1.32-5.66, P = 0.002, model C-index 0.764, Akaike Information Criterion [AIC] 797), as were PHI risk category changes over time (risk category 4 [vs. 1] HR 4.20, 95% CI 1.76-10.05, P = 0.002, C-index 0.759, AIC 489). Separate models with baseline PSAD and PSAD changes over time yielded C-indices of 0.709 (AIC 809) and 0.733 (AIC 495) respectively. CONCLUSIONS: Baseline PHI risk category and PHI changes over time were both independent predictors of GR after confirmatory biopsy, but the added benefit over PSAD seemed modest. However, baseline PHI and PHI risk category changes provided clinically useful risk stratification for time to GR, so further evaluation of PHI's ability to help reduce the frequency of mpMRI and/or surveillance biopsies with more PHI data points over time may be warranted.

Clinical Significance of Perineural Invasion in Men With Grade Group 1 Prostate Cancer on Active Surveillance.

PURPOSE: We aimed to evaluate the clinical significance of perineural invasion in men on active surveillance for Grade Group 1 prostate cancer. MATERIALS AND METHODS: We identified 1,969 men with Grade Group 1 prostate cancer and at least 1 follow-up biopsy. A time-dependent Cox model and a logistic regression model were used to assess the association between biopsy-detected perineural invasion and grade reclassification (defined as the detection of Grade Group ≥2 prostate cancer on a surveillance biopsy), and adverse pathology (defined as Grade Group ≥3 ± seminal vesicle invasion ± lymph node involvement) at radical prostatectomy, respectively. RESULTS: The 198 men with perineural invasion detected during active surveillance had lower rates of grade reclassification-free survival than those without perineural invasion (P < .001). On multivariable analysis perineural invasion was significantly associated with grade reclassification (HR 3.25, 95% CI 2.54-4.16, P < .001); an association that persisted in the multiparametric magnetic resonance imaging subset. At radical prostatectomy, men with biopsy-detected perineural invasion had more extraprostatic extension than men without perineural invasion (Relative Risk 1.71, 95% CI 1.15-2.56). However, on multivariable analysis biopsy-detected perineural invasion was not associated with adverse pathology (OR 0.68, 95% CI 0.27-1.68, P = .40) and these patients did not exhibit more biochemical recurrence at 5 years (P > .05). CONCLUSIONS: Perineural invasion during active surveillance was associated with grade reclassification. At radical prostatectomy biopsy-detected perineural invasion patients exhibited more extraprostatic extension but biopsy-detected perineural invasion was not independently associated with more adverse pathology. In addition, these patients did not have more biochemical recurrence during follow-up. Perineural invasion should not preclude Grade Group 1 patients from active surveillance but they may warrant more stringent monitoring.

Risk prediction tool for grade re-classification in men with favourable-risk prostate cancer on active surveillance.

OBJECTIVE: To create a nomogram for men on active surveillance (AS) for prediction of grade re-classification (GR) above Gleason score 6 (Grade group >2) at surveillance biopsy. PATIENTS AND METHODS: From a cohort of men enrolled in an AS programme, a multivariable model was used to identify clinical and pathological parameters predictive of GR. Nomogram performance was assessed using receiver operating characteristic curves, calibration, and decision curve analysis. RESULTS: Of 1 374 men, 254 (18.50%) were re-classified to Gleason ≥7 on surveillance prostate biopsy. Variables predictive of GR were earlier year of diagnosis [≤2004 vs ≥2005; odds ratio (OR) 2.16, P < 0.001], older age (OR 1.05, P < 0.001), higher prostate-specific antigen density [OR 1.19 (per 0.1 unit increase), P = 0.04], bilateral disease (OR 2.86, P < 0.001), risk strata (low-risk vs very-low-risk, OR 1.79, P < 0.001), and total number of biopsies without GR (OR 0.68, P < 0.001). On internal validation, a nomogram created using the multivariable model had an area under the curve of 0.757 (95% confidence interval 0.730-0.797) for predicting GR at the time of next surveillance biopsy. CONCLUSION: The nomogram described is currently being used at each return visit to assess the need for a surveillance biopsy, and could increase retention in AS.