Active surveillance for low-risk prostate cancer with high tumor burden at biopsy: lessons learned from a contemporary radical prostatectomy cohort.

Introduction: To investigate whether initial tumor burden at biopsy could predict adverse features after radical prostatectomy (RP) in International Society of Urological Pathology (ISUP) 1 prostate cancer (PCa) patients.

Methods: This retrospective study was conducted in six referral centers. The cohort included patients with ISUP 1 PCa at systematic and MRI-targeted biopsy. We defined a high tumor burden at biopsy if ≥ 20% of cores were positive. The endpoint of the study was adverse features at RP, defined as ≥ pT3a stage and/or N1 and/or ISUP ≥ 3. Sensitivity analyses were performed to assess associations between different thresholds on biopsy (percentage of positive cores [PPC] ≥ 25%, ≥ 33%, ≥ 50%, bilateral positivity and positive cores > 3) and adverse features. As the number of targeted biopsies sampled may influence the number of positive cores, we used a virtual biopsy model in which all targeted biopsy results were interpreted as a single targeted biopsy.

Results: A total of 312 contemporary patients were included. At final pathology, 99 patients (32%) had adverse features. In multivariate logistic regression analysis, there was no statistical association between PPC > 20% and adverse features (OR = 1.22; 95%CI:0.69-2.22, p = 0.5). In sensitivity analysis, tumor burden at biopsy was not associated with the risk of adverse features, regardless of the definition used (all p > 0.05). When we considered a unique virtual targeted biopsy, tumor burden remained not associated with adverse features (all p > 0.05).

Conclusions: ISUP 1 PCa tumor burden at biopsy did not predict adverse features in this study, suggesting that it should not be used alone as an exclusion criterion when assessing eligibility for active surveillance.