Utilization and Quality Outcomes of cT1a, cT1b and cT2a Partial Nephrectomy: Analysis of the National Cancer Database

To describe utilization and compare quality outcomes of partial nephrectomy (PN) for cT1a, cT1b and cT2a renal mass using a large national database.

Retrospective analysis of patients from the US National Cancer Database who underwent PN for cT1a/cT1b/T2a renal cell carcinoma between 2004-2013. We examined utilization of PN over time and quality indicators [positive surgical margin (PSM) and 30-day postoperative readmission rates (30Day-Readmit)]. Multivariable analysis was utilized to elucidate predictors for outcome comparisons.

43,749 patients underwent PN for cT1a, cT1b and cT2a renal mass (34,796 cT1a; 8,040 cT1b; 913 cT2a). Proportion undergoing PN increased from 30.8% in 2004 to 56.7% in 2013 (p<0.001), reflected all clinical stages. PSM rate was 6.8%. Predictive factors for increased risk of PSM included cT1a stage (p=0.03), age (OR 1.01, p<0.001) and later year of diagnosis (OR 1.05, p<0.001). 30Day-Readmit was 4.2%. Predictive factors for increased risk of readmission included cT1b (p<0.001), high Charlson comorbidity score (OR 1.32, p=0.001) and lack of private insurance (OR 1.21-1.97, p<0.05); later year of diagnosis was associated with decreased odds of readmission (OR 0.96, p<0.001). Subset analysis of 2010-2013 cohort revealed increases in proportion of Minimally Invasive (MIS) PN for cT1a (52.8% to 69.6%, p<0.001), cT1b (39.9% to 59.6%, p <0.001) and cT2a tumors (33.3% to 47.3%, p=0.01). PSM rate was increased at 7.3%. Predictive factors for PSM included increasing age (OR 1.01, p<0.001), MIS approach (OR 1.52, p<0.0013), and conversion to open surgery (OR 1.52, p=0.01), but not clinical stage (p=0.75-0.99). 30Day-Readmit was 4.0%. Predictive factors for re-admission included lack of private insurance (p<0.001), and conversion to open surgery (OR 1.63, p<0.001).

PN utilization has increased significantly for all clinical stage groups. Over time, PSM rates increased while 30Day-Readmit rates decreased. PSM rate increase was driven by increasing utilization of MIS approaches, and not higher clinical stage. 30Day-Readmit was driven by patient co-morbidities and socioeconomic factors. Rising PSM rates represent a quality of care concern. This article is protected by copyright. All rights reserved.

BJU international. 2017 Oct 15 [Epub ahead of print]

Katherine Fero, Zachary A Hamilton, Ahmet Bindayi, James D Murphy, Ithaar H Derweesh

Departments of Radiation Medicine, University of California San Diego School of Medicine, La Jolla, California, USA., Urology and Radiation Medicine, University of California San Diego School of Medicine, La Jolla, California, USA.