Oncologic Outcomes Of Complete Transurethral Resection Prior To Neoadjuvant Chemotherapy For Muscle-Invasive Bladder Cancer.

e17029 Background: Neoadjuvant chemotherapy (NAC) prior to radical cystectomy (RC) is the standard of care for muscle-invasive bladder cancer (MIBC). Prior studies have shown that pT0 response at RC can be attributed to NAC and high-quality transurethral resections (TURBT) prior to NAC. Therefore, we sought to assess the association of completeness of pre-NAC TURBT with response and survival outcomes. Methods: This was a single-institution, retrospective review of patients who received NAC for clinically localized MIBC (≥cT2, N0) from 2000 to 2017. Exclusion criteria were receipt of non-cisplatin-based NAC or radiation (n = 15), and insufficient documentation of TURBT (n = 26). Complete TURBT (cTURBT) was defined as tumor resection in entirety and/or resection to normal appearing muscle in operative reports, or repeat pre-NAC TURBT revealing clinical T0 (cT0). After NAC, patients either underwent repeat TURBT or immediate RC, as per the treating physician. Patients refusing RC were placed on an active surveillance/delayed intervention (ASDI) protocol of cytology, cystoscopy, and imaging at 3-4 month intervals. Primary endpoint was durable complete response (dCR): pT0 at RC or remaining cT0 on ASDI for ≥1 year. Secondary endpoints included OS and durable down-staging (dDS): ≤pT1 at RC or remaining ≤cT1 on ASDI for ≥1 year. Results: Of a total 93 patients, 62 (67%) underwent pre-NAC cTURBT. Those with cTURBT had lower rates of variant histology (13% vs 32%, p = 0.03), hydronephrosis (15% vs 39%, p < 0.01), and more often pursued ASDI (60% vs 26%, p = 0.01). Patients with cTURBT were more likely to attain dCR (37% vs 13%, p = 0.01) and dDS (60% vs. 26%, p < 0.01). On multivariate (MV) analysis, cTURBT was a significant predictor of dCR and dDS; this remained true on subset analysis excluding 11 patients with ≥cT3 on restaging TURBT. On Kaplan-Meier analysis, patients with cTURBT had improved 5-year OS (78% vs. 46%, p < 0.01). On MV analysis controlling for variant histology, lymphovascular invasion, and hydronephrosis, cTURBT was the only significant predictor of OS, also on subset analysis excluding the 11 patients with ≥cT3 on restaging TURBT. Conclusions: A pre-NAC cTURBT is associated with improved oncologic outcomes and OS in this MIBC cohort. The extent to which cTURBT represents a selection criterion for having lower clinical stage or a therapeutic advantage in response to NAC is difficult to isolate from a retrospective study. However, this study suggests cTURBT should be pursued when feasible to potentially optimize outcomes after NAC.