The prognostic value of pathologic prostate-specific antigen mass ratio in patients with localized prostate cancer with negative surgical resection margins.

OBJECTIVE To investigate potential predictors of biochemical recurrence (BCR) in patients with localized prostate cancer with negative surgical resection margin (SRM). MATERIALS AND METHODS Data from 582 consecutive patients diagnosed with localized prostate cancer with negative SRM who underwent only radical prostatectomy between November 2003 and April 2010 were reviewed. Pathologic prostate-specific antigen (PSA) mass ratio was defined as total circulating PSA protein per surgical prostate volume. Cox regression models tested the association between clinicopathologic variables and BCR-free survival. RESULTS Mean age at surgery was 64.9 ± 6.9 years and mean PSA was 8.3 ± 4.4 ng/mL. The mean follow-up period was 40.7 ± 7.9 months. Pathologic stage was T2a in 113 of 582 patients (19.3%), T2b in 4 of 582 (0.7%), and T2c in 465 of 582 (79.9%). Surgical Gleason score was ≤6 in 215 of 582 patients (37.0%), 7 in 342 of 582 (58.8%), and ≥8 in 25 of 582 (4.3%). Mean pathologic prostate volume and pathologic PSA mass ratio were 42.4 ± 15.8 mL (14.6-176.0 mL) and 0.48 ± 0.37 μg/mL (0.03-2.62 μg/mL), respectively. Five-year BCR-free survival rate was 90.9%. PSA, surgical Gleason score, and pathologic PSA mass ratio were significantly associated with BCR-free survival in univariate analysis. In multivariate analysis, surgical Gleason score (P <.001, hazards ratio = 9.804) and pathologic PSA mass ratio (P = .037, hazards ratio = 3.753) were independent predictors of BCR-free survival. CONCLUSION In patients with localized prostate cancer and negative SRM after radical prostatectomy, surgical Gleason score and pathologic PSA mass ratio were significant prognostic indicators of BCR-free survival.