Index Density of Percentage of Biopsy Positive Cores, the Ratio of Percentage of Biopsy Positive Cores on Prostate Volume, has a Strong Prognostic Impact on Clinical Prostate Cancer Progression After Robotic Surgery: Results in 1047 Consecutive Patients Treated in a Single Tertiary Referral Centre

Background/Objectives: To evaluate index density (Id) of percentage of biopsy positive cores (BPC), the ratio of BPC on prostate volume (Id-BPC), as a prognostic factor of clinical prostate cancer (PCa) progression after robotic surgery. Methods: The study included 1047 consecutive patients who were treated in a period ranging from January 2013 to December 2021. The risk of disease progression, which was defined as at least the occurrence of biochemical and/or loco-regional and metastases recurrence, was evaluated by Cox’s proportional hazards. Results: Disease progression, which occurred in 237 (22.6%) patients after a mean (95% CI) follow-up of 82.5 (80.1 – 84.9) months, was predicted by Id-BPC which was stronger than BPC itself; accordingly, as biopsy tumor load densities increased, so patients were more likely to experience disease progression not only after adjusting for clinical variables (hazard ratio = 1.55; 95% CI: 1.32 – 1.83; p < 0.0001), but also for un-favorable pathology (hazard ratio = 1.37; 95% CI: 1.21 – 1.56; p < 0.0001), as well. Con-clusions: The risk of clinical PCa progression after robotic surgery was independently predicted by Id-BPC which was stronger than BPC; accordingly, as Id-BPC increased so patients were more likely to experience disease progression; likewise, Id-BPC could be a useful clinical marker of cancer biology.