Treatment Of Metastatic Recurrence Of Urothelial Carcinoma After Previous Cisplatin-Based Chemotherapy: A Retrospective Comparison Of Different Chemotherapy Regimens.

e17005 Background: The optimal choice of first-line chemotherapy for urothelial carcinoma (UC) patients who recur after previous cisplatin-based chemotherapy for locally-advanced disease is unclear. Our objective is to compare the efficacy of platinum (PBC) versus non-platinum (NPBC) based first-line chemotherapy regimens for such patients after metastatic recurrence. Methods: Data was collected from the Retrospective International Study of Cancers of the Urothelial Tract (RISC), a database consisting of patients with muscle-invasive or advanced UC from 28 centers between 2005 and 2012. Patient inclusion criteria included: 1) UC with no initial metastases (cT2-4, cN0-N3, and cM0), 3) receipt of cisplatin in the locally advanced setting, and 4) receipt of chemotherapy in the first-line metastatic setting. Overall survival (OS) was the primary endpoint. Secondary endpoints included progression-free survival (PFS) and response to chemotherapy. Kaplan-Meier and Cox regression models estimated OS, PFS, and response, adjusting for age, gender, Eastern Cooperative Oncology Group (ECOG-PS), Charlson comorbidity index (CCI), surgery, T and N stage, albumin, creatinine clearance, number of initial cisplatin cycles, and time from last chemotherapy. Results: 152 patients with metastatic UC (88 PBC and 64 NPBC) were analyzed. Twelve (7.9%) patients received local definitive radiation and 7 of these 12 also underwent cystectomy. The most common NPBC regimens included taxanes, gemcitabine, or pemetrexed. The median OS was 8.70 (95% CI: 7.53 to 11.16) and 10.27 months (95% CI: 7.37 to 13.10) for PBC and NPBC (HR: 1.04, 95% CI: .67 – 1.61, p = 0.86), respectively. Multivariable analysis showed an independent prognostic effect on OS for number of previous chemotherapy cycles (3-4 vs. 1-2) (HR: 0.44, 95% CI 0.20 – 0.96, P = 0.03) and whether surgery was performed (HR: 0.44, 95% CI 0.26 – 0.75, P = 0.003). Time from last chemotherapy was not prognostic for OS (HR: 0.99, 95% CI: 0.99 – 1.00, p = 0.19). There were no significant differences for both investigator-designated PFS (HR: 0.84, 95% CI: 0.57 – 1.24, p = .39) and response to chemotherapy between PBC and NPBC (p = 0.57). Conclusions: There is no significant outcome difference between PBC vs. NPBC in patients with metastatic-recurrent urothelial carcinoma who previously received cisplatin-based chemotherapy for locally advanced disease. Those who previously underwent radical surgery or who received 3-4 cycles of cisplatin had better OS with PBC.