Incident CKD after Radical or Partial Nephrectomy

Abstract

The comparative effectiveness of partial nephrectomy versus radical nephrectomy to preserve kidney function has not been well established. We determined the risk of clinically significant (stage 4 and higher) CKD after radical or partial nephrectomy among veterans treated for kidney cancer in the Veterans Health Administration (2001-2013). Among patients with preoperative eGFR≥30 ml/min per 1.73 m², the incidence of CKD stage 4 or higher after radical (n=9759) or partial nephrectomy (n=4370) was 7.9% overall. The median time to stage 4 or higher CKD after surgery was 5 months, after which few patients progressed. In propensity score-matched cohorts, partial nephrectomy associated with a significantly lower relative risk of incident CKD stage 4 or higher (hazard ratio, 0.34; 95% confidence interval [95% CI], 0.26 to 0.43, versus radical nephrectomy). In a parallel analysis of patients with normal or near-normal preoperative kidney function (eGFR≥60 ml/min per 1.73 m²), partial nephrectomy was also associated with a significantly lower relative risk of incident CKD stage 3b or higher (hazard ratio, 0.15; 95% CI, 0.11 to 0.19, versus radical nephrectomy) in propensity score-matched cohorts. Competing risk regression models produced consistent results. Finally, patients treated with a partial nephrectomy had reduced risk of mortality (hazard ratio, 0.55; 95% CI, 0.49 to 0.62). In conclusion, compared with radical nephrectomy, partial nephrectomy was associated with a marked reduction in the incidence of clinically significant CKD and with enhanced survival. Postoperative decline in kidney function occurred mainly in the first year after surgery and appeared stable over time.

Keywords: Nephrectomy; chronic kidney disease; kidney cancer.

Graphical abstract

Figure 1.

The incidence of kidney function outcomes was greater among patients treated with radical nephrectomy when compared with patients receiving partial nephrectomy in the full analytic cohort (n=14,129). (A) Over a median follow-up of 40 months (25th, 75th percentile, 15–74 months), 183 of 4370 (4.2%) patients experienced stage 4 or higher CKD after partial nephrectomy compared with 938 of 9759 (9.6%) after radical nephrectomy. (B) In 8089 patients with normal or near-normal kidney function, 96 of 2849 (3.7%) experienced stage 3b CKD or higher after partial nephrectomy compared with 1053 of 5240 (20.1%) after radical nephrectomy. (C) The median time to kidney function event was 5 months (25th, 75th percentile, 4–9 months) in the full cohort. (D) In patients with normal or near-normal preoperative kidney function, the median time to stage 3b CKD was 5 months (25th, 75th percentile, 4–8 months).

Figure 2.

A contour plot of the density of 440,582 postoperative eGFR measurements after either radical or partial nephrectomy illustrates the stability of kidney function measurements over time in the full cohort. The density of eGFR measurements is illustrated by each contour. The linear trend for kidney function over time is reflected by the regression lines.

Figure 3.

The incidence of kidney function outcomes following either partial or radical nephrectomy for the propensity score–matched cohort (n=5908). (A) Over a median follow-up of 38 months (25th, 75th percentile, 16–68 months), 83 patients experienced stage 4 or higher CKD after partial nephrectomy compared with 212 after radical nephrectomy (log-rank P<0.001). (B) In the propensity score–matched cohort of 3680 patients with normal or near-normal kidney function, 62 experienced stage 3b or higher CKD after partial nephrectomy compared with 354 after radical nephrectomy (log-rank P<0.001).

Figure 4.

Patients treated with partial nephrectomy demonstrated improved overall survival in each of the propensity score–matched cohorts. (A) The primary propensity score–matched cohort (preoperative kidney function eGFR>30 ml/min per 1.73 m²); (B) additionally matched by clinical T stage; (C) patients with normal or near-normal kidney function (eGFR>60 ml/min per 1.73 m²); and (D) additionally matched by tumor T stage. PSM, Propensity Score-Matched.