Temporal trends and socioeconomic determinants of cytoreductive nephrectomy (CN) utilization for metastatic renal cell carcinoma (mRCC) in the United States (US).

447 Background: The evolving treatment landscape in mRCC since the advent of tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs) has rendered the role of CN unclear. We sought to quantify CN utilization in the US over the past two decades and assess factors that affect equitable access to CN. Methods: We performed an analysis of the National Inpatient Sample database, using ICD-9 and ICD-10 diagnostic and procedure codes to identify mRCC patients undergoing CN from 2006 to 2021. We calculated annual CN utilization rates, stratified by demographic and socioeconomic factors. We then performed univariable and directed acyclic graph-guided multivariable logistic regression analyses to determine the effect of demographic, socioeconomic, and clinical factors on CN utilization rates. Results: There has been a significant decrease in CN utilization in 2021 compared to 2006 (8.7% vs. 15.8%; OR 0.51, 95% CI 0.42-0.61), consistent across all demographic and socioeconomic groups. Factors associated with decreased CN utilization include Black race (OR 0.70, 95% CI 0.64-0.76), Hispanic race (OR 0.87, 95% CI 0.80-0.95), female gender (OR 0.94, 95% CI 0.90-0.98), being a Medicare (aOR 0.69, 95% CI 0.64-0.73) or Medicaid beneficiary (aOR 0.59, 95% CI 0.54-0.64), lowest income quartile (aOR 0.84, 95% CI 0.78-0.90), Southern US location (aOR 0.83, 95% CI, 0.74-0.93), and treatment in small-sized (aOR 0.57, 95% CI 0.51-0.63) or rural hospitals (aOR 0.33, 95% CI 0.27-0.40). CN utilization has significantly decreased during the ICI era compared to the TKI era (OR 0.69, 95% CI 0.64-0.75). Conclusions: CN utilization has steadily declined across the US over the past two decades, reflecting the uncertainty surrounding its role in mRCC management as new systemic therapies emerge. Access to CN is marked by significant demographic and socioeconomic disparities. Defining the evolving role of CN in the current mRCC treatment era and addressing these disparities is crucial to optimize patient outcomes. Characteristic Univariable analysis(OR [95% CI]) p -value Multivariable analysis(aOR [95% CI]) p -value Black race (ref. White) 0.70 (0.64-0.76) <0.001 - - Hispanic race (ref. White) 0.87 (0.80-0.95) 0.001 - - Female gender (ref. male) 0.94 (0.90-0.98) 0.008 - - 1 st quartile income (ref. 4 th quartile) 0.79 (0.73-0.85) <0.001 0.84 (0.78-0.90) <0.001 Medicare (ref. private insurance) 0.55 (0.53-0.58) <0.001 0.69 (0.64-0.73) <0.001 Medicaid (ref. private insurance) 0.58 (0.54-0.63) <0.001 0.59 (0.54-0.64) <0.001 Southern US (ref. Northeastern US) 0.82 (0.73-0.92) 0.001 0.83 (0.74-0.93) 0.002 Small hospital (ref. large hospital) 0.56 (0.50-0.62) <0.001 0.57 (0.51-0.63) <0.001 Rural hospital (ref. urban teaching hospital) 0.32 (0.27-0.38) <0.001 0.33 (0.27-0.40) <0.001