Background: Partial cystectomy (PC) offers potential benefits for select patients with muscle-invasive bladder cancer (MIBC). However, the oncologic efficacy of PC may be compromised due to the underutilization of standard-of-care modalities, such as neoadjuvant chemotherapy (NAC) and pelvic lymphadenectomy (PLND). We aimed to assess factors influencing the incorporation of NAC and PLND with PC and evaluate their impact on overall survival (OS). Methods: We identified patients with cT2-4N0M0 BCa who underwent PC between 2004 and 2019 using the National Cancer Database (NCDB). The primary endpoint was OS. Kaplan-Meier analysis compared OS between PC patients who did and did not receive NAC. Multivariate Cox Proportional Hazards (CPH) model assessed the impact of age, sex, race, insurance, income, Charlson-Deyo Index (CDI), clinical T-stage, facility type, histology, surgical margins, NAC, PLND adequacy (≥10 LN yield), and adjuvant radiation treatment on OS. Multivariate logistic regressions were performed to examine predictors of NAC and PLND receipt in PC patients. Results: Of 2,832 patients included, 231 (8.1%) patients received multi-agent NAC with PC and had improved median OS compared to those who did not (115.0 vs. 87.4 months, p<0.001). This finding persisted in the adjusted CPH model, where private insurance, NAC, and PLND significantly improved OS, especially when PLND yielded ≥10LN. Conversely, age >80, CDI >2, cT3-4, positive margins, and adjuvant radiation all increased adjusted mortality risk. After controlling for clinicopathologic variables, females were less likely to receive PLND (OR=0.634, p<0.001), while NAC was more likely administered to PC patients diagnosed from 2015-2019 (OR=2.177, p=0.022). PC patients who received NAC were more likely to have PLND performed as part of their treatment regimen (OR=2.189, p<0.001). Additionally, patients treated at academic centers were more likely to have NAC administered and PLND performed (OR=1.745, p=0.003; OR=2.465, p<0.001, respectively). Conclusions: Despite guidelines, there is an insufficient utilization of NAC and PLND when performing PC. Our analysis underscores the significant OS benefit of these recommended treatments as part of MIBC care. Importantly, we highlight a gradual increase in NAC and PLND receipt in recent years, centered largely at academic facilities. Notably, gender disparities exist in PLND receipt, emphasizing the need for further investigation.

*Model adjusted for clinicodemographic variables.