Sarcomatoid Urothelial Carcinoma Is Associated With Limited Response to Neoadjuvant Chemotherapy and Poor Oncologic Outcomes After Radical Cystectomy.

INTRODUCTION: To examine oncologic outcomes and response to neoadjuvant chemotherapy (NAC) in patients with sarcomatoid urothelial carcinoma (SUC) treated with radical cystectomy (RC). MATERIALS AND METHODS: We retrospectively queried our institutional database (2003-18) and Surveillance, Epidemiology, and End Results (SEER)-Medicare (2004-2015) for patients with cT2-4, N0-2, M0 SUC and conventional UC (CUC) treated with RC. Clinicopathologic characteristics were described using descriptive statistics (t test, χ2-test and log-rank-test for group comparison). Overall (OS) and recurrence-free-survival (RFS) after RC were estimated with the Kaplan Meier method and associations with OS were evaluated with Cox proportional hazards models. RESULTS: We identified 38 patients with SUC and 287 patients with CUC in our database, and 190 patients with SUC in SEER-Medicare. In the institutional cohort, patients with SUC versus CUC had higher rates of pT3/4 stage (66% vs. 35%, P < 0.001), lower rates of ypT0N0 (6% vs. 35%, P = .02), and worse median OS (17.5 vs. 120 months, P < .001). Further, patients with SUC in the institutional versus SEER-Medicare cohort had similar median OS (17.5 vs. 21 months). In both cohorts, OS was comparable between patients with SUC undergoing NAC+RC vs. RC alone (17.5 vs. 18.4 months, P = .98, institutional cohort; 24 vs. 20 months, P = .56, SEER cohort). In Cox proportional hazards models for the institutional RC cohort, SUC was independently associated with worse OS (HR 2.3, CI 1.4-3.8, P = .001). CONCLUSION: SUC demonstrates poor pathologic response to NAC and worse OS compared with CUC, with no OS benefit associated with NAC. A unique pattern of rapid abdominopelvic cystic recurrence was identified.

Response to Neoadjuvant Chemotherapy and Survival in Micropapillary Urothelial Carcinoma: Data From a Tertiary Referral Center and the Surveillance, Epidemiology, and End Results (SEER) Program.

BACKGROUND: Micropapillary urothelial carcinoma (MPC) is a rare urothelial carcinoma variant with conflicting data guiding clinical practice. In this study, we explored oncologic outcomes in relation to neoadjuvant chemotherapy (NAC) in a retrospective cohort of patients with MPC, alongside data from Surveillance, Epidemiology, and End Results (SEER)-Medicare. PATIENTS AND METHODS: We retrospectively identified patients with MPC or conventional urothelial carcinoma (CUC) without any variant histology undergoing radical cystectomy (RC) in our institution (2003-2018). SEER-Medicare was also queried to identify patients diagnosed with MPC (2004-2015). Clinicopathologic data and treatment modalities were extracted. Overall survival (OS) was estimated with the Kaplan-Meier method. Mann-Whitney-Wilcoxon and chi-square tests were used for comparative analysis and Cox regression for identifying clinical covariates associated with OS. RESULTS: Our institutional database yielded 46 patients with MPC and 457 with CUC. In SEER-Medicare, 183 patients with MPC were identified, and 63 (34%) underwent RC. In the institutional cohort, patients with MPC had significantly higher incidence of cN+ (17% vs. 8%), pN+ stage (30% vs. 17%), carcinoma-in-situ (43% vs. 25%), and lymphovascular invasion (30% vs. 16%) at RC versus those with CUC (all P < .05). Pathologic complete response (ypT0N0) to NAC was 33% for MPC and 35% for CUC (P = .899). Median OS was lower for institutional MPC versus CUC in univariate analysis (43.6 vs. 105.3 months, P = .006); however, MPC was not independently associated with OS in the multivariate model. Median OS was 25 months in the SEER MPC cohort for patients undergoing RC, while NAC was not associated with improved OS in that group. CONCLUSION: Pathologic response to NAC was not significantly different between MPC and CUC, while MPC histology was not an independent predictor of OS. Further studies are needed to better understand biological mechanisms behind its aggressive features as well as the role of NAC in this histology variant.