Renal and cardiovascular morbidity after partial or radical nephrectomy

BACKGROUND. To clarify the benefits of nephron-sparing surgery among patients with early-stage kidney cancer, the authors compared the frequency of renal and cardiovascular morbidity after partial or radical nephrectomy. METHODS. This retrospective cohort study was based on linked Surveillance, Epidemiology, and End Results -Medicare data. The authors identified 10,886 patients who underwent partial or radical nephrectomy between 1991 and 2002. Medical claims were examined for the occurrence of adverse renal and/or cardiovascular outcomes, and multivariate survival models were fit to estimate the association between type of surgery and each clinical outcome, using propensity scores to balance the treatment cohorts with respect to measured patient and disease characteristics. To control for secular trends in the indications for partial nephrectomy, separate analyses were performed based on treatment era (1991-1999 or 2000-2002). RESULTS. During the study interval, 10,123 patients (93%) and 763 patients (7%) underwent radical or partial nephrectomy, respectively. During 2000 to 2002, patients who underwent partial nephrectomy experienced fewer adverse renal outcomes (16.4% vs 21.8%; adjusted hazard ratio, 0.74; 95% confidence interval, 0.58-0.94), including a trend toward less frequent receipt of dialysis services, dialysis access surgery, or renal transplantation. The likelihood of adverse cardiovascular outcomes did not differ by treatment. CONCLUSIONS. Among contemporary patients, partial nephrectomy was associated with less clinically apparent renal morbidity than radical nephrectomy. This finding motivates expanded use of partial nephrectomy among patients with early-stage kidney cancer. Given the potential for selection bias and residual confounding in this observational cohort, additional prospective studies will be necessary to validate the current findings.