or pN+ urothelial carcinoma of the bladder previously treated with neoadjuvant chemotherapy

32nd Annual EAU Congress, 24-28 March 2017, London, United Kingdom

172

Adjuvant chemotherapy vs. observation following radical cystectomy for pT3-4 and/or pN+ urothelial carcinoma of the bladder previously treated with neoadjuvant chemotherapy Eur Urol Suppl 2017; 16(3);e289

Seisen T.1, Jamzadeh A.2, Vetterlein M.1, Von Landenberg N.1, Gild P.1, Menon M.2, Rouprêt M.3, Sun M.1, Choueiri T.4, Bellmunt J.4, Trinh Q.-D.1 1

Brigham and Women's Hospital, Harvard Medical School, Division of Urological Surgery and Center For Surgery and Public Health, Boston, United States of America, 2Henry Ford Health System, VUI Center For Outcomes Research, Analytics and Evaluation, Vattikuti Urology Institute, Detroit, United States of America, 3Pitié-Salpêtrière, APHP, University Paris VI, Department of Urology, Paris, France, 4Dana Farber Cancer Institute, Dept. of Medical Oncology, Boston, United States of America INTRODUCTION & OBJECTIVES: Neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) is the standard of care for clinically localized muscle-invasive urothelial carcinoma of the bladder (UCB). Approximately 20% of patients who received NAC + RC have adverse features on pathology, specifically pT3-4 and/or N+ disease. Against this backdrop, we examine the role of adjuvant chemotherapy (AC) following RC for those pretreated with NAC. MATERIAL & METHODS: Within the National Cancer Data Base (2004-2012), we identified 800 patients who received AC vs. observation following NAC plus RC for pT3/T4N0 or pN+ UCB. Multiple imputation using chained equations was used to handle missing data. We further performed inverse probability of treatment weighting (IPTW)-adjusted Kaplan-Meier and Cox regression analyses with a 6-month conditional landmark to compare overall survival (OS) between the two treatment groups. Specifically, propensity scores derived from a logistic regression model predicting the receipt of AC vs. observation were used to weigh each patient to balance observable characteristics. RESULTS: Overall, 190 (23.8%) vs. 610 (76.2%) patients underwent AC vs. observation following NAC + RC, respectively. Independent predictors of receiving AC vs. observation included facility type (Nonacademic vs. academic: OR=2.08, 95%CI=[1.45-2.97]; P<0.001) and location (West vs. Est; OR=1.84; 95%CI=[1.12-3.01]; P=0.016), as well as disease stage (pTanyN+ vs. pT3N0: OR=2.18; 95%CI=[1.47-3.22]; P<0.001), while older age (OR=0.97; 95%CI=[0.94-0.99]; P=0.008) predicted the opposite. IPTW-adjusted Kaplan-Meier curves showed that median OS was significantly improved in the AC vs. observation group (29.9 [IQR, 15.1-85.4] vs. 24.2 [IQR, 12.9-58.9] months; P=0.031; Figure 1). The 5-year IPTW-adjusted rates of OS for AC vs. observation were 36.8% vs. 24.7%, respectively. In IPTW-adjusted Cox regression analyses, AC was associated with a significant OS benefit (HR=0.76; 95%CI=[0.60-0.97]; P=0.031).

Eur Urol Suppl 2017; 16(3);e289

32nd Annual EAU Congress, 24-28 March 2017, London, United Kingdom

172

Adjuvant chemotherapy vs. observation following radical cystectomy for pT3-4 and/or pN+ urothelial carcinoma of the bladder previously treated with neoadjuvant chemotherapy Eur Urol Suppl 2017; 16(3);e290

CONCLUSIONS: We report an OS benefit for individuals treated with AC vs. observation for pT3-4 and/or N+ UCB following NAC + RC. Our findings warrant further consideration in randomized controlled trials to explore this hypothesis.

Eur Urol Suppl 2017; 16(3);e290 Powered by TCPDF (www.tcpdf.org)