Trends and variations in utilization of nephron-sparing procedures for stage I kidney cancer in the United States.

Purpose: The incidental detection of early-stage kidney tumors is increasing in the United States. Nephron-sparing approaches (NS) to managing these tumors are equivalent to radical nephrectomy (RN) in oncologic outcomes and have a decreased impact on renal function. Our objective was to evaluate trends in the use of NS over the past decade and the socioeconomic factors associated with its use.
Methods: The National Cancer Database was queried to identify patients with stage I kidney cancer between 2000 and 2008. Patients were classified by the type of surgery as NS (local destruction and local excision) or RN. Patients were further categorized by age, race, insurance status, and income. Log-binomial regression was used to estimate prevalence ratios (PR) for the proportion of NS to RN according to demographic and socioeconomic characteristics.
Results: From 2000 to 2008, there were 142,194 cases of kidney cancer reported to the NCDB. In these cases, 43,034 (30.3 %) patients had NS, and 86,431 (60.78 %) patients had RN. The prevalence of NS increased 10 % per year (PR = 1.10, p < 0.0001)-from 20.0 % in 2000 to 45.1 % in 2008. Older age, lower income, Black race, Hispanic ethnicity, and lack of health insurance were associated with a decreased prevalence of NS.
Conclusions: NS as a treatment for stage I kidney cancer has increased steadily since 2000. Age, racial, and socioeconomic differences may exist in the utilization of NS. Additional analyses, with patient level data, are required to address the independent significance of these variables in an effort to develop strategies to mitigate these potential disparities.