Impact of the Proportion of Biopsy Positive Core in Predicting Biochemical Recurrence in Patients with Pathological Pt2 and Negative Resection Margin Status after Radical Prostatectomy

This study aimed to determine the prognostic factors associated with biochemical recurrence (BCR) after radical prostatectomy (RP) in patients with pathological T2 (pT2) prostate cancer (PCa) and negative resection margin (RM) status at a single institution. In this retrospective study, we examined 386 patients who were diagnosed with pT2 PCa with negative RM after RP. The length of the tumor was provided for each biopsy core and the overall percentage of PCa was calculated by a pathologist at our institution. We estimated the BCR-free survival (BRFS) in these patients. Univariate and multivariate analyses were performed using the Cox proportional hazard model to determine the risk factors of BCR. The median age of the participants was 68 years, and their initial prostate-specific antigen level was 6.55 ng/mL. The median follow-up period was 85.7 months. The 5-year BRFS rate of the participants was 89.0%. The 5-year BRFS rates were 89.8% in patients with a biopsy Gleason score of 6, 90.4% in those with 7, and 64.1% in those with >= 8 (P = 0.007). The BRFS rate was 93.3% in patients who had a biopsy positive core <= 20% and 82.0% in those who had >= 21% (P = 0.001). Based on the multivariate analysis, the proportion of biopsy positive core was significantly associated with BCR. The proportion of biopsy positive core may predict preoperative covariates in patients with pT2 PCa and negative RM status after RP.