Percent tumor volume predicts biochemical recurrence after radical prostatectomy: Multi-institutional data analysis

Background To investigate the prognostic significance of percent tumor volume (PTV) in relation to the surgical margin status in men with prostate cancer after radical prostatectomy (RP). Methods Clinical and pathological data from 1,567 patients treated with RP only between 1995 and 2007 at participating institutions were reviewed. PTV was determined by the sum of all visually estimated tumor foci on every section. Biochemical recurrence (BCR) was defined as 2 consecutive increases in prostate-specific antigen (PSA) >0.2 ng/ml and various clinicopathological variables were tested for prognostication of recurrence-free survival. Results Serum PSA at surgery was 12.5 ± 16.8 ng/ml and pathological stage was T2 in 899 (57.4%) patients. Surgical Gleason score was 7 in 842 patients (53.7%), higher than 7 in 250 (16%) patients, and in 32% of the patients, surgical margin was positive. Mean PTV was 15.7% and demonstrated a significant positive correlation with serum PSA, all pathological variables and BCR. On multivariate analysis, preoperative PSA (p = 0.012), surgical Gleason score (p<0.0001, HR 2.183, 95% CI 1.778-2.681), and PTV (≥5, 5.1-15, >15%; p<0.0001, HR 1.393, 95% CI 1.183-1.641) were independently prognostic of recurrence-free survival. Pathological stage demonstrated a significant relationship with BCR but was not independently prognostic in the multivariate model. Conclusion In men with prostate cancer, preoperative PSA, surgical Gleason score, and PTV are independent predictors of recurrence-free survival after RP.