A population-based comparison of survival after nephrectomy vs nonsurgical management for small renal masses

To examine population-based rates of cancer-specific and other-cause mortality after either non-surgical management (NSM) or nephrectomy, in patients with small renal masses, as several reports from selected institutions support the applicability of surveillance in patients with small renal masses, but there are no population-based studies confirming the general applicability of this therapy. Of 43 143 patients with renal cell carcinoma identified in the 1988-2004 Surveillance, Epidemiology and End Results database, 10 291 had localized small renal masses (<= 4 cm) and were offered NSM (433, 4.2%) or nephrectomy (9858, 95.8%). Univariable matched and multivariable unmatched competing-risks regression models were used in the analyses. Cumulative incidence plots based on unmatched data, where the effect of other-cause mortality was controlled for, showed a 5.2%, 6.5% and 9.4% survival benefit for nephrectomy vs NSM at 1, 2 and 5 years after nephrectomy or diagnosis, respectively. The same magnitude of the benefit (4.5%, 5.6% and 8.0%) persisted in analyses matched for age, tumour size and year of diagnosis or of nephrectomy. Finally, in multivariable analyses, treatment type, age, tumour size and year of diagnosis or of nephrectomy were independent predictors. Relative to nephrectomy, NSM appears to undermine the overall and cancer-specific survival of patients with small renal masses by as much as 9.4%, at 5 years.