Index density of positive biopsy cores is associated with post-robotic cancer progression

Antonio Benito Porcaro¹, Maria Angela Cerruto^1,*, Alberto Bianchi¹, Francesco Artoni¹, Francesca Montanaro¹, Alberto Baielli¹, Filippo Caudana¹, Andrea Franceschini¹, Alessandro Veccia¹, Riccardo Rizzetto¹, Matteo Brunelli², Riccardo Giuseppe Bertolo¹, Alessandro Antonelli¹
1 Department of Urology, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
2 Department of Pathology, University of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
* Corresponding Author: Maria Angela Cerruto. Email: email
(This article belongs to the Special Issue: Prostate Cancer: Biomarkers, Diagnosis and Treatment)

Canadian Journal of Urology https://doi.org/10.32604/cju.2026.081303

Received 27 February 2026; Accepted 16 June 2026; Published online 20 July 2026

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Abstract

Background: Current prognostic stratification of prostate cancer (PCa) does not fully capture disease heterogeneity. Common biopsy-based parameters, such as the percentage of biopsy positive cores (BPC), do not account for prostate volume (PV). This study aims to evaluate the association between the index density of biopsy positive cores (Id-BPC), defined as the ratio of BPC to prostate volume, and disease progression after robot-assisted radical prostatectomy (RARP). Materials and Methods: We retrospectively analyzed 1047 consecutive PCa patients treated with RARP between January 2013 and December 2021. Inclusion criteria were: ≥12 systematic biopsy cores, available PV measurement, and follow-up data. Patients with prior therapies were excluded. Disease progression (biochemical recurrence/persistence and/or loco-regional or distant recurrence) was analyzed using Cox proportional hazards models. Results: Disease progression occurred in 237 patients (22.6%) after a mean follow-up of 82.5 months. Id-BPC was significantly associated with disease progression and showed larger effect size estimates than BPC when evaluated in separate models (HR = 1.47; 95% CI: 1.29–1.67; p < 0.001). Higher Id-BPC values were also associated with unfavorable pathology (HR = 1.37; 95% CI: 1.21–1.56; p < 0.001). Conclusions: Id-BPC is independently associated with PCa progression after RARP and may provide additional prognostic information beyond BPC. It may represent a clinically useful marker of tumor aggressiveness.