Presentation Authors: Ken Chow*, Pia Herrera, Ryan Stuchbery, Justin S. Peters, Anthony J. Costello, Christopher M. Hovens, Niall M. Corcoran, Melbourne, Australia
Introduction: Radical prostatectomy is the preferred initial treatment for localized prostate cancer in 45% of men with localized prostate cancer in the United States. Although the majority experience long term disease control, current literature reports that up to a third of men will develop disease recurrence. Given the profound changes that have occurred in prostatectomy cohorts due to the rise of active surveillance for low risk disease, we aimed to characterize the pattern of late disease recurrence in a largest contemporary cohort.
Methods: Consecutive patients who underwent radical prostatectomy between 2003 and 2017 for localized prostate cancer were identified from a prospectively recorded, dedicated prostate cancer database. Patients who received neo-adjuvant androgen deprivation therapy were excluded. Patients were categorized into no recurrence; < 12 months (early); 12-60 months (intermediate); and >60 months (late). Clinicopathological characteristics were analyzed using Mann-Whitney U test, Student&[prime]s t-test, or Chi-square tests where appropriate. In order to assess predictors of recurrence at various time-points, multivariable binomial logistic regression models were utilized.
Results: A total of 2312 patients were included with up to 12 years of follow up data. The average patient had clinically localized prostate cancer, an elevated PSA, and had biopsy ISUP grade group 2. At prostatectomy, 88.7% of patients had ISUP grade group â‰¥2. A subgroup of 446 patients had undetectable PSA levels at 5 years after prostatectomy; 11.7% of them progressed to experience biochemical recurrence. In this subgroup, late recurrers had significantly higher-grade tumors on ISUP and Gleason sum (p = < 0.001 and p = 0.001, respectively), larger tumor volumes (p = 0.032), and higher rates of extraprostatic extension (p = 0.022). Prostatectomy ISUP grade group was demonstrated as being a significant predictor on logistic regression (OR 2.14, 95% CI 1.43-3.20, p = < 0.001).
Conclusions: This study characterizes the pattern of late recurrence in the largest contemporary active surveillance era cohort. We have identified that prostatectomy ISUP grade group is a strong predictive indicator for late recurrence. We also propose that timing of recurrence resides on a continuum of risk and that the potential concept of dormant micrometastatic involvement requires further research and evaluation.