Does size matter? Comparing robotic versus open radical nephrectomy for very large renal masses.

Abstract

We evaluated perioperative and mortality outcomes of robotic-assisted radical nephrectomy (RRN) vs. open radical nephrectomy (ORN) for very large renal cell carcinomas (RCC). Adult patients with non-metastatic RCC >10 cm in size (pT2b) were identified from the National Cancer Database (2010-2017). Mixed-effects multivariable logistic regression adjusting for patient, tumor, and facility characteristics were used to evaluate rates of positive margin, prolonged length of stay (LOS) (>75th percentile), 30-day readmission, and 30-day and 90-day mortality for RRN vs. ORN. Overall survival (OS) was evaluated using the Kaplan-Meier method and adjusted Cox proportional hazard modeling. Of the 2,977 patients who underwent radical nephrectomy, 492 (16.5%) underwent RRN. Factors associated with RRN included male gender, metro or urban locations, academic facilities, Charlson-Deyo score >2, private or Medicaid insurance, and surgery in a later year (all P < 0.05). Tumors ≥15.1cm in size were associated with a higher rate of conversion to open surgery (P < 0.001). ORN was associated with increased median postoperative LOS (4d [interquartile range; IQR 3-6] vs. 3d, [IQR 2-4]; P < 0.01). RRN demonstrated no significant difference in the risk of positive margin, 30-day readmission, 30-day mortality, or 90-day mortality. RRN was associated with a decreased risk of prolonged LOS (OR 0.38; 95%CI [0.28-0.53]). There was no difference in long-term OS observed in patients treated with ORN vs. RRN. Very large, non-metastatic RCC can be safely and effectively treated with RRN. Rates of conversion to open were higher for tumors ≥15.1 cm. RRN has comparable long-term OS and improved LOS compared to ORN.