UCSF

Purpose

Renal cell carcinoma is increasingly diagnosed at stage I, and among stage I cases mean tumor size has been decreasing. Previous reports suggest that nephron sparing surgery is underused for small renal cell carcinomas. We determined updated, population based treatment trends for stage I renal cell carcinoma.

Materials and methods

The National Cancer Data Base, which captures approximately 70% of all cancer diagnoses in the United States, was queried for renal cell carcinoma in adults diagnosed between 1993 and 2007. Trends in treatment, including no surgery, total nephrectomy, partial nephrectomy and focal ablation, were analyzed among all stage I tumors and small stage I tumors categorized by size. Logistic regression was used to identify predictors of nephron sparing surgery (partial nephrectomy or focal ablation).

Results

During the study period we identified 242,740 renal cell carcinomas, of which 127,691 were stage I. For all stage I tumors partial nephrectomy increased from 6.3% to 32.2% of cases and ablation increased from 1.0% to 6.8%. For tumors less than 2.0, 2.0 to 2.9 and 3.0 to 3.9 cm partial nephrectomy increased from 15.3% to 61.1%, 11.0% to 44.2% and 7.2% to 31.1%, respectively (each p<0.001). Female gender, black race, Hispanic ethnicity, lower income, older age and treatment at community hospitals were associated with lower use of nephron sparing.

Conclusions

While total nephrectomy is still likely overused for small renal cell carcinoma, nephron sparing surgery for stage I renal cell carcinoma has increased substantially in the last 15 years with about 4-fold increases across tumor sizes. These trends appear to be ongoing but sociodemographic disparities exist which must be rectified.