Login to Access Video or Poster Abstract: MP72-09
Sources of Funding: none

Introduction

Emerging data from centers of excellence suggests that partial nephrectomy (PN) for cT1b and cT2a Renal Cell Carcinoma (RCC) are oncologically safe and may confer renal functional benefit. We sought to study trends in utilization and short term quality outcomes of PN among patients with cT1b and cT2a RCC using the National Cancer Database (NCDB).

Methods

We identified 39,561 patients with localized cT1b or cT2a RCC who underwent PN from 2004-2013. Primary outcome was utilization of PN over time. Secondary outcomes included hospital length of stay (LOS, short hospitalization: 0-4 days), margin status and 30-day readmissions. Cochrane-Armitage test was used to describe trends over time. Multivariable (MVA) logistic regression models were used to investigate associations between tumor stage and outcomes.

Results

The study consisted of 28,620 (72.3%) patients with cT1b and 10,941 (27.7%) with cT2a masses. Overall, 8,953 (22.6%) patients underwent PN. More patients with cT1b vs. cT2a tumors underwent PN (28.1% vs. 8.34%; p<0.01). PN increased over the study period (cT1b: 13.7% to 37.1%, p<0.01; cT2a: 3.2% to 11.0%, p<0.01; Figure). For all PN, positive margin rates increased from 4.3% in 2004 to 6.8% in 2013, (p<0.01); 30-day readmission was not significantly changed (2.2% in 2004 to 5.1% in 2013, p=0.76). Proportion of short LOS increased, from 51.6% in 2004 to 75.2% in 2013 (p<0.01). MVA for positive margins was notable for increasing age (OR 1.01, p=0.012), year of diagnosis (OR 1.07, p=0.01), and facility type (comprehensive community OR 1.362, p=0.002, integrated network cancer program OR 1.53, p=0.009, free standing cancer center program OR 3.44, p=0.003). MVA for 30-day readmission demonstrated high Charlson score (OR 1.38, p=0.046), and facility type (integrated network cancer program OR 0.56, p=0.022) as being significant. On MVA, patients with cT2a tumors were no more likely than those with cT1b to require 30-day readmission (OR 0.86, p=0.36) or have positive margins (OR 0.96, p=0.75).

Conclusions

Utilization of PN for cT1b and cT2a renal mass has increased over time. While length of hospital stay has shortened and 30-day readmission rates are not significantly different, an increase in positive margin rates has been noted, with predictive factors including patient age and facility type. PN in cT2a does not confer increased risk compared to PN in cT1b RCC. Focused emphasis and strategies to reduce positive margin rates in this higher risk population of localized renal masses should be considered.

Funding

none