Should partial nephrectomy be considered "elective" in patients with stage 2 chronic kidney disease? A comparative analysis of functional and survival outcomes after radical and partial nephrectomy.

Purpose: To compare renal function and survival outcomes in patients with baseline chronic kidney disease (CKD) stage 2 undergoing partial (PN) or radical nephrectomy (RN), as nephron-sparing surgery is considered to be elective in this group.

Methods: Retrospective analysis of patients with CKD stage 2 and T1/T2 renal mass undergoing PN or RN from 2001 to 2015. Patients were stratified into substage CKD 2a or CKD 2b and analyzed between types of surgery. Primary outcome was overall survival (OS), eGFR < 45 at last follow-up was the secondary outcome. Multivariable analysis (MVA) was conducted for predictors of eGFR < 45 and OS. Kaplan-Meier analyses were conducted for freedom from eGFR < 45 and OS.

Results: 1213 patients analyzed (CKD 2a 609/CKD 2b 604) on MVA, RN (OR 3.68, p = 0.001) and CKD 2b (OR 3.3, p = 0.002) were independently associated with development of eGFR < 45 at last follow-up and RN (OR 3.76, p = 0.005) and eGFR < 45 (OR 2.51, p = 0.029) were associated with decreased OS. Kaplan-Meier analyses revealed that patients with CKD 2a/PN had the highest 5-year freedom from eGFR < 45 (94.3%) compared to CKD 2a/RN patients (91.5%), CKD2b/PN patients (87.6%) and CKD 2b/RN patients 82.0% (p < 0.001). Kaplan-Meier analyses for OS demonstrated that patients with CKD 2a/PN had significantly greater 5-year OS (97.6%) compared to CKD 2a/RN patients (95.2%), CKD 2b/PN patients (93.2%), and CKD 2b/RN patients (92.4%, p = 0.043).

Conclusions: Patients with baseline CKD stage 2, particularly CKD 2b and undergoing RN, are at increased risk of GFR < 45, which was associated with decreased OS. In patients with CKD 2b, a nephron-sparing strategy is indicated and should be prioritized when feasible.