Presentation Authors: Sebastian Berg*, Boston, MA, David D'Andrea, Vienna, Austria, Malte Wolfram Vetterlein, Hamburg, Germany, Alexander Putnam Cole, Sean Anthony Fletcher, Marieke Johanna Krimphove, Maya Marchese, Stuart R. Lipsitz, Guru Sonpayde, Boston, MA, Joachim Noldus, Herne, Germany, Shahrokh F. Shariat, Vienna, Austria, Adam S. Kibel, Quoc-Dien Trinh, Matthew Mossanen, Boston, MA
Introduction: The use of adjuvant chemotherapy (AC) in pure urothelial carcinoma of the bladder is established. Regarding variant histology, there is a gap in knowledge concerning the optimal treatment after radical cystectomy (RC). The objective of our study was to assess the effect of AC on overall survival (OS) in patients with pure urothelial carcinoma, urothelial carcinoma with concomitant variant histology, or other pure variant histology.
Methods: : Within the National Cancer Database, 15,397 patients who underwent RC for non-metastatic localized carcinoma of the bladder with positive lymph nodes (T2 N+) or locally advanced stage (â‰¥T3 N0/+) were identified, excluding those who underwent prior neoadjuvant chemotherapy. Multivariable Cox regression models were used to examine the specific effect of AC on OS stratified by each distinct histological subtype: pure urothelial carcinoma, micropapillary or sarcomatoid differentiation, squamous cell carcinoma, adenocarcinoma and neuroendocrine tumors. To account for immortal time bias, Cox regression analyses as well as Kaplan-Meier analyses were conducted with a landmark at three months.
Results: In multivariable landmark analyses, AC compared to initial observation was associated with an OS benefit for pure urothelial carcinoma (Hazard Ratio [HR]=0.87, 95% confidence interval [CI] 0.82-0.91), whereas no differences were observed with regard to variant histology.
Conclusions: Multivariable Cox regression landmark analysis revealed a survival benefit of AC for patients with a pure urothelial carcinoma. However, a survival benefit of AC for patients with urothelial carcinoma having concomitant variant histology or for other pure variant histology was not demonstrated.
Source of Funding: Brigham Research Institute, Bruce A. Beal and Robert L. Beal Surgical Fellowship, Conquer Cancer Foundation, Defense Health Agency, Intuitive Surgical, Prostate Cancer Foundation, Vattikuti Urology Institute.