The volume of Gleason grade group 1 prostate cancer at biopsy predicts unfavorable pathology but not upgrading after radical prostatectomy.

[PURPOSE] To investigate whether volume of Gleason grade group 1 (GGG1) prostate cancer at prostate biopsy predicts unfavorable pathologic findings after radical prostatectomy (RP).

[METHODS] We retrospectively reviewed clinical and pathologic data from patients with biopsy-confirmed GGG1 prostate cancer and prostate-specific antigen < 20 ng/mL who underwent RP at our institution between May 2014 and May 2023. The percentage of positive biopsy cores (PPC) was defined as the number of cancer positive cores divided by the total number of cores at biopsy. The primary outcome was unfavorable pathology at RP, defined as ≥ GGG3, and/or pT3/4, and/or pN1. Gleason upgrading (≥ GGG2) and biochemical recurrence after RP were also evaluated. Multivariable logistic regression analyses were performed to assess the association between PPC and the risk of unfavorable pathology and Gleason upgrading.

[RESULTS] A total of 213 patients were analyzed. Median PPC was 17.0%. Unfavorable pathology was observed in 41.8%, while 53.1% had Gleason upgrading. PPC ≥ 17% was significantly associated with unfavorable pathology (odds ratio = 1.02; p = 0.030), but not with Gleason upgrading (odds ratio = 1.01; p = 0.189). The 5-year biochemical recurrence-free survival was 98.2% for PPC < 17% and 97.8% for PPC ≥ 17%, with no significant difference between the groups (log-rank p = 0.417).

[CONCLUSION] Higher PPC was associated with unfavorable pathologic outcomes, but not with upgrading or recurrence, in biopsy-confirmed GGG1 prostate cancer patients treated with RP.