A novel nomogram to identify candidates for active surveillance amongst patients with International Society of Urological Pathology (ISUP) Grade Group (GG) 1 or ISUP GG2 prostate cancer, according to multiparametric magnetic resonance imaging findings

Abstract

Objectives To develop a novel nomogram to identify candidates for active surveillance (AS) that combines clinical, biopsy and multiparametric magnetic resonance imaging (mpMRI) findings; and to compare its predictive accuracy to, respectively: (i) Prostate Cancer Research International: Active Surveillance (PRIAS) criteria, (ii) Johns Hopkins (JH) criteria, (iii) European Association of Urology (EAU) low‐risk classification, and (iv) EAU low‐risk or low‐volume with International Society of Urological Pathology (ISUP) Grade Group (GG) 2 classification. Patients and Methods We selected 1837 patients with ISUP GG1 or GG2 prostate cancer (PCa), treated with radical prostatectomy (RP) between 2012 and 2018. The outcome of interest was the presence of unfavourable disease (i.e., clinically significant PCa [csPCa]) at RP, defined as: ISUP GG ≥3 and/or pathological T stage (pT) ≥3a and/or pathological N stage (pN) 1. First, logistic regression models including PRIAS, JH, EAU low‐risk, and EAU low‐risk or low‐volume ISUP GG2 binary classifications (not eligible vs eligible) were used. Second, a multivariable logistic regression model including age, prostate‐specific antigen density (PSA‐D), ISUP GG, and the percentage of positive cores (Model 1) was fitted. Third, Prostate Imaging‐Reporting and Data System (PI‐RADS) score (Model 2), extracapsular extension (ECE) score (Model 3) and PI‐RADS + ECE score (Model 4) were added to Model 1. Only variables associated with higher csPCa rates in Model 4 were retained in the final simplified Model 5. The area under the receiver operating characteristic curve (AUC), calibration plots and decision curve analyses were used. Results Of the 1837 patients, 775 (42.2%) had csPCa at RP. Overall, 837 (47.5%), 986 (53.7%), 348 (18.9%), and 209 (11.4%) patients were eligible for AS according to, respectively, the EAU low‐risk, EAU low‐risk or low‐volume ISUP GG2, PRIAS, and JH criteria. The proportion of csPCa amongst the EAU low‐risk, EAU low‐risk or low‐volume ISUP GG2, PRIAS and JH candidates was, respectively 28.5%, 29.3%, 25.6% and 17.2%. Model 4 and Model 5 (in which only PSA‐D, ISUP GG, PI‐RADS and ECE score were retained) had a greater AUC (0.84), compared to the four proposed AS criteria (all P < 0.001). The adoption of a 25% nomogram threshold increased the proportion of AS‐eligible patients from 18.9% (PRIAS) and 11.4% (JH) to 44.4%. Moreover, the same 25% nomogram threshold resulted in significantly lower estimated risks of csPCa (11.3%), compared to PRIAS (Δ: −14.3%), JH (Δ: −5.9%), EAU low‐risk (Δ: −17.2%), and EAU low‐risk or low‐volume ISUP GG2 classifications (Δ: −18.0%). Conclusion The novel nomogram combining clinical, biopsy and mpMRI findings was able to increase by ~25% and 35% the absolute frequency of patients suitable for AS, compared to, respectively, the PRIAS or JH criteria. Moreover, this nomogram significantly reduced the estimated frequency of csPCa that would be recommended for AS compared to, respectively, the PRIAS, JH, EAU low‐risk, and EAU low‐risk or low‐vo...

Role of Multiparametric Prostate Magnetic Resonance Imaging before Confirmatory Biopsy in Assessing the Risk of Prostate Cancer Progression during Active Surveillance

“…MRI is also useful in predicting the time from progression to active treatment. This capacity has allowed various groups to propose nomograms to select not only GG 1 patients, but also GG 2 patients for AS (12).…”

“…However, the study protocol during the follow-up of an AS patient was considerably different from the current protocols, which could invalidate the conclusion (9). To improve the safety of AS programs, some tools (10) and risk calculators (11,12) have been explored with mixed results. Further studies and recalibrations are still warranted to increase the widespread use of such programs.…”

Predictors of ISUP score upgrade in patients with low-risk prostate cancer

“…The use of multiparametric magnetic resonance imaging (mpMRI) of the prostate has increased significantly over the years in active surveillance. 30 Luzzago et al 31 developed a nomogram based on mpMRI findings to select the patients suitable for active surveillance. However, mpMRI findings of patients could not be included in our study due to the lack of data for all patients.…”

Characteristics of Cancer Progression on Serial Biopsy in Men on Active Surveillance for Early-stage Prostate Cancer: Implications for Focal Therapy

“…A deeper understanding of its biology and natural history has led to the acceptance of active surveillance (AS) as a safe option for well-selected men with clinically localized PCa [2]. AS has been proposed for patients with a grade group (GG) 1 disease, but recently, men with low-volume GG2 have been included [3,4].…”