A total of 7,051 patients who underwent radical prostatectomy between September 1998 and December 2016 in Western Australia were divided into a high-grade group, defined as Gleason sum 4 + 3, 8 and 9 or greater and ISUP (International Society of Urological Pathology) groups 3, 4 and 5, and a low grade group, defined as Gleason sum 6 or less and 3 þ 4, and ISUP groups 1 and 2. The t-test and the Pearson chi-square test were used to evaluate differences between transition zone and peripheral/central zone cancer. The Kaplan-Meier method with the log-rank test was used to determine differences in biochemical recurrence-free survival at 5 years in patients with the high-grade disease. Univariate and multivariable Cox proportional hazard regression analyses were performed. Model calibration was determined by the internal validation method.
High-grade transition zone cancer was associated with significantly increased prostate specific antigen, tumor volume and incidence of positive surgical margins but a lower incidence of intraductal carcinoma, extraprostatic spread, seminal vesicle invasion, lymph node involvement and biochemical failure after radical prostatectomy. Patients with low-grade prostate cancer had excellent biochemical recurrence-free survival regardless of tumor origin. The high-grade multivariable model had a c-index of 0.78 and improved predictive accuracy, particularly for high-grade transition zone disease.
Transition zone tumor origin independently and positively impacts biochemical outcomes of high-grade prostate cancer. A high grade postoperative prognostic model including transition zone tumor origin as an independent predictor was developed and predictive accuracy was significantly improved in patients with high grade, transition zone disease.
Patrick E. Teloken, Jian Li, Clifton G. Woods and Ronald J. Cohen*
Department of Urology (PET), Princess Alexandra Hospital, Brisbane, Queensland and Uropath Pty Ltd (JL, CGW, RJC) and School of Pathology and Laboratory Medicine (RJC), University of Western Australia, Western Australia, Australia
The Impact of Prostate Cancer Zonal Origin on Pathological Parameters at Radical Prostatectomy and Subsequent Biochemical Failure Teloken, Patrick E. et al. The Journal of Urology, Volume 198, Issue 6, 1316 - 1323
Go Beyond the Abstract - Read a Commentary by Zhamshid Okhunov, MD, University of California Irvine