Zonal origin of prostate cancer: comparison of long-term outcomes after radical prostatectomy

PURPOSE: To assess the impact of zonal origin on positive bladder neck (BN) margins and prostate-specific antigen (PSA) failure or early adjuvant therapy in the patients with complete long-term follow-up after radical prostatectomy (RP). METHODS: A set of 4512 men were identified who underwent RP in Western Australia (WA) from March 2000 to December 2016 and had complete long-term follow-up. The t-test, Pearson chi-square test and Kaplan–Meier method with the log-rank test were used to evaluate differences between the transition zone (TZ) and peripheral/central zone (PZ/CZ) cancer. Univariate and multivariable Cox proportional hazard regression models were applied to assess parameters on PSA failure and early treatment. RESULTS: The positive BN margin rate for TZ cancer fell significantly over the study period. However, BN margin rates increased for PZ/CZ cancer over the time. Data of 4512 patients with median follow-up of 9.1 years confirmed that the high-risk TZ tumours with negative margins had a significant lower rate of PSA failure or early treatment compared to those high-risk PZ/CZ tumours with negative margins. CONCLUSION: Prostate cancer zonal origin significantly impacts long-term biochemical outcomes in high-risk and margin-negative patients. BN invasion with margin involvement is more frequent in the TZ cancer and can be reduced by pre-operative identification of cancer zonal origin and adjustment of surgical procedures.