Abstracts from the Mid-Atlantic Section of the AUA 2020

© The Canadian Journal of Urology TM : International Supplement, October 2020 MP4-02 Differences in Testosterone Suppression for In Situ Gel vs. Microsphere Delivered Leuprolide Acetate – An Analysis of US Clinical Data L. Gordan 1 ; S. Atkinson 2 ; D. Boldt-Houle 2 ; N. Shore 3 1 Florida Cancer Specialists & Research Institute, Gainesville, FL, USA; 2 Tolmar Pharmaceuticals, Inc., Buffalo Grove, IL, USA; 3 Atlantic Urology Clinics, Myrtle Beach, SC, USA Introduction: Suppressing testosterone (T) to the levels attained with surgical castration is the cornerstone of androgen deprivation therapy (ADT) for advanced prostate cancer (PCa). However, Tmay rise above castrate level (50ng/dL) between injections, especially if a subsequent dose is delayed. Delivery systems should be considered, as ADT therapies are not necessarily interchangeable. Two FDA approved forms of leuprolide acetate (LA) use different extended release systems: an in situ gel technology (Gel-LA, subcutaneous) and microsphere technology (Msphere-LA, intramuscular). This study evaluated the prevalence of late dosing and the comparative impact of late dosing on T suppression for Gel-LA and Msphere-LA. Materials & Methods: A retrospective analysis of US oncology and urology electronicmedical records (1/1/07-6/30/16) of PCa patients who receivedGel-LAor Msphere-LAinjections evaluated the frequency of late dosing (defined as occurring after day 32, 97, 128, 194 for 1-, 3-, 4-, 6-month formulations, respectively), mean T and rate of T tests > 50 ng/dL with late dosing. Results: 2,038 patients received Gel-LA and 8,360 received Msphere-LA. 27% of injections for both drugs were late. When dosing was late, mean T was 48 ng/dL (Gel-LA) vs. 76 ng/dL (Msphere-LA). 18% (Gel-LA) vs. 25% (Msphere-LA) of T valueswere > 50 ng/dL. Both of these analyseswere statistically significant (p < 0.05). Conclusions: Overall, more than a quarter of injections were administered late. With late dosing, Gel-LA was more effective than Msphere-LA at maintaining T suppression, as demonstrated by lower mean T and lower rates of T breakthrough > 50 ng/dL.Althoughmodifying clinical practice procedures to increase adherence to dosing schedules is recommended, late injections are ubiquitous in real world practice.As higher T levels, including T escapes, have potential to adversely impact disease progression and survival, clinicians should reassess their dosing schedule compliance policies and utilize an ADT which optimizes the goal of effective castrate levels of T suppression. MP4-01 Comparison of Oncologic Outcomes for Robotic vs. Open Radical Cystectomy Among Clinically Node-Positive Patients: An Analysis of the National Cancer Database (NCDB) A. Reddy 1 ; A. Sparks 2 ; C. Darwish 1 ; M. Whalen 1 1 George Washington University School of Medicine and Health Sciences, Washington, DC, USA; 2 George Washington UniversityMedical Faculty Associates, Washington, DC, USA Introduction: Given the putative mechanism of peritoneal immunomodulation and tumor cell intravasation induced by pneumoperitoneum, the increased risk of atypical nodal recurrence after robotic-assisted radical cystectomy (RARC) may be more significant for those with node-positive muscle invasive bladder cancer (MIBC). This study aims to understand differences in mortality and post-operative outcomes of RARC compared to more conventional, open radical cystectomy (ORC) in this population. Materials & Methods: A retrospective cohort analysis of cT2-4N1-3M0 patients who underwent RARC or ORC was performed using the NCDB from 2010- 2016. Populations were further sub-stratified based on receipt of neoadjuvant chemotherapy (NAC). Appropriate univariate and multivariable analysis was performed comparing respective cohorts. Proportion of RARC by year was analyzed for treatment trends. Results: 657 ORC and 163 RARC cases met inclusion criteria. There was no difference in overall survival between cohorts (Figure, Table). RARC was more common in recent years (Spearman’s ρ = 0.09; P = 0.01) and was associated with significantly increased lymph node yield relative to ORC (nodes examined > 14, 58% vs. 45%; P = 0.03). RARC was significantly associated with shorter inpatient stay in the overall population (Table) and in those who received NAC (median 7 vs. 8 days; P = 0.02). Among patients who did not receive NAC, RARC was associated with decreased odds of positive margin status (adjusted odds ratio=0.49; P = 0.05). Conclusions: The utilization of RARC has continued to increase from 2010 to 2016 and is no less safe compared to ORC in node-positive MIBC. RARC demonstrated similar outcomes to ORC for several endpoints regardless of NAC administration and may confer surgical and perioperative benefits. Poster Session 4: Oncology Treatment and Outcomes 30