Presentation Authors: Ashwin Balakrishnan*, Shoujun Zhao, Janet Cowan, Jeanette Broering, Matthew Cooperberg, Peter Carroll, San Francisco, CA
Introduction: Evidence regarding the use of adjuvant therapy for patients with adverse features at radical prostatectomy (RP) has evolved over the years. The aims of this study were to determine trends and predictors of adjuvant therapy in patients with adverse features at RP, and to investigate the association between adjuvant therapy and prostate cancer specific morality (PCSM).
Methods: From the CaPSURE registry (1990-2017), 2084 men with adverse features (pT3N0M0 disease and/or positive surgical margins) at RP were identified. Adjuvant therapy was defined as external beam radiation therapy (EBRT) and/or androgen deprivation therapy (ADT) at â‰¤6 months after RP without a prostate specific antigen (PSA) level of >0.1 ng/mL, and salvage therapy as EBRT and/or ADT at >6 months after RP or a PSA level of >0.1 ng/mL before initiation of therapy. Temporal trends were evaluated, and predictors of adjuvant therapy were assessed with multivariate logistic regression. Competing risks regression was used to test for cumulative incidence and risk of PCSM.
Results: Of 2084 men with adverse features at RP, 87 (4.2%), 73 (3.5%), and 25 (1.2%) received adjuvant ERBT alone, ADT alone, or combined EBRT and ADT, respectively. Of these 2084 men, 412 (19.8%) received salvage EBRT and/or ADT. Adjuvant treatment for patients with adverse features at RP decreased from 14.5% in 1990-94 to 5% or less in 2005-17 (p-trend < 0.001, see figure), while salvage treatment decreased from 35.2% in 1990-94 to less than 7% in 2005-17 (p-trend < 0.001). Adverse feature type and year of diagnosis were significantly associated with receipt of adjuvant therapy (p < 0.001). There was significant variability in the hazard of PCSM by adverse feature type. Compared to patients with positive surgical margins, patients with seminal vesicle involvement had approximately two times greater hazard of PCSM (HR, 1.97; 95% CI 1.06 - 3.66; p=0.033).
Conclusions: Adjuvant therapy has declined for men found to have pathologically staged T3 disease and/or positive surgical margins, without a corresponding rise in salvage therapy. Variable outcomes by adverse feature type suggest that treatment guidelines could be strengthened by accounting for differences in risk associated with each adverse feature type.
Source of Funding: Grant from US Department of Defense Prostate Cancer Research Program (W81XWH-13-2-0074)