Trends in usage of cytoreductive partial nephrectomy and effect on overall survival in patients with metastatic renal cell carcinoma.

PURPOSE: Cytoreductive radical nephrectomy (cRN) improves survival in select patients with metastatic renal cell carcinoma (mRCC). It is unclear, however, whether cytoreductive partial nephrectomy (cPN) compromises oncologic efficacy. We evaluated trends in utilization of cPN and compared overall survival (OS) in patients who underwent cRN or cPN for mRCC.

MATERIALS AND METHODS: We queried the National Cancer Database from 2006 to 2013 and identified patients who underwent cPN and cRN for mRCC. We analyzed rates of cPN over time. Logistic regression identified predictors of cPN. We matched patients based on propensity score for treatment. We used matched Kaplan-Meier survival analyses to compare OS, stratified by tumor size. We used multivariable Cox proportional hazards models to determine the effect of cPN and cRN on OS.

RESULTS: A total of 10,144 patients met inclusion criteria, with 9,764 (96.2%) undergoing cRN and 381 (3.8%) undergoing cPN. Rates of cPN increased over time from 1.8% to 4.3% over the study period. Treatment at an academic/research facility, papillary and chromophobe histology, and more recent year of treatment were associated with increased odds of cPN. In a matched survival analysis, cPN was associated with improved OS compared with cRN (log rank, P = 0.001). This effect was limited to primary tumors<4cm. In a propensity-score adjusted multivariable Cox model, cPN was associated with improved OS (hazard ratio = 0.81; 95% CI: 0.71-0.93; P = 0.002).

CONCLUSIONS: The use of cPN in patients with mRCC is increasing. cPN is associated with improved OS in patients with mRCC, although this effect is limited to patients with primary tumors<4cm.