Assessing Functional Outcomes of Partial Versus Radical Nephrectomy for T1b-T2 Renal Masses: Results from a Multi-institutional Collaboration

Background: Deterioration of renal function is associated with increased all-cause mortality. In renal masses larger than 4 cm, whether partial versus radical nephrectomy (PN vs. RN) might affect long-term functional outcomes is unknown. This study tested the association between PN versus RN and postoperative acute kidney injury (AKI), recovery of at least 90% of the preoperative estimated glomerular filtration rate (eGFR) at 1 year, upstaging of chronic kidney disease (CKD) one stage or more at 1 year, and eGFR decline of 45 ml/min/1.73 m2 or less at 1 year. Methods: Data from 23 high-volume institutions were used. The study included only surgically treated patients with single, unilateral, localized, clinical T1b-2 renal masses. Multivariable logistic regression analyses were performed. Results: Overall, 968 PN patients and 325 RN patients were identified. The rate of AKI was lower in the PN versus the RN patients (17% vs. 58%; p < 0.001). At 1 year after surgery, for the PN versus the RN patients, the rate for recovery of at least 90% of baseline eGFR was 51% versus 16%, the rate of CKD progression of ≥ 1 stage was 38% versus 65%, and the rate of eGFR decline of 45 ml/min/1.73 m2 or less was 10% versus 23% (all p < 0.001). Radical nephrectomy independently predicted AKI (odds ratio [OR], 7.61), 1-year ≥ 90% eGFR recovery (OR, 0.30), 1-year CKD upstaging (OR, 1.78), and 1-year eGFR decline of 45 ml/min/1.73 m2 or less (OR, 2.36) (all p ≤ 0.002). Conclusions: For cT1b-2 masses, RN portends worse immediate and 1-year functional outcomes. When technically feasible and oncologically safe, efforts should be made to spare the kidney in case of large renal masses to avoid the hazard of glomerular function loss-related mortality.