Nephron-sparing surgery (NSS) for patients with renal tumors preserves kidney function and reduces the risk of end-stage renal disease (ESRD) compared with radical nephrectomy (RN), a new study suggests.
Using a collaborative database, Umberto Capitanio, MD, of University Vita-Salute, San Raffaele Scientific Institute in Milan, Italy, and colleagues determined the ESRD rate and predictors among 2,207 patients free of pre-existing chronic kidney disease (CKD) who had surgery for nonmetastatic clinical T1 unilateral kidney cancer during 1984–2010 at 5 centers in Europe. Of these, 1,334 (65.8%) underwent NSS and 693 (34.2%) underwent RN with limited or no hilar clamping. The mean follow-up was 72 months.
Unadjusted ESRD rates at 5 and 10 years were similar in the NSS group (1.5% and 2.5%, respectively) and the RN group (1.9% and 2.7%, respectively), according to a paper published online in European Urology. In multivariate analysis, however, NSS was associated with a significant 60% decreased risk of ESRD compared with RN, after adjusting for baseline characteristics affecting CKD risk, such as age diabetes, uncontrolled hypertension, and other comorbidities. The median time to ESRD, which was defined as an estimated glomerular filtration rate less than 15 mL/min/1.73 m2, was 45 months.
The authors added that an even greater benefit is possible with the novel surgical techniques of no clamp or selective clamping, which were described recently in a paper published in The Lancet (2016;387:894-906).
Preoperative medical conditions are the most important determinants for ESRD, according to the researchers. Previous studies, which found little difference in ESRD risk between NSS and RN, did not account for such comorbidities or tumor size.
Dr Capitanio and colleagues noted that a recent subanalysis of 514 patients included in a European Organization for Research and Treatment of Cancer (EORTC) randomized trial found that the incidence of ESRD was nearly identical for patients treated with NSS or RN (1.6% vs. 1.5%). This study, which was published in European Urology (2014;65:372-377), included patients treated prior to 2003, when surgical experience with NSS techniques and outcomes were limited, Dr Capitanio’s group pointed out. In addition, some patients had preoperative impaired renal function. The current series included patients treated more recently, had normal preoperative renal function, and who did not have hilar clamping or who had limited clamping. “Those main differences may explain the discordance between the benefit we found in the NSS group and the EORTC trial findings,” Dr Capitanio and colleagues wrote.
Strengths of the current study include its multi-institutional design, the relatively long follow-up, and the inclusion of patients without baseline CKD, Dr Capitanio’s team noted. Limitations include the study’s retrospective design, which cannot exclude the presence of residual confounders, such as proteinuria at diagnosis.
- Capitanio U, Larcher A, Terrone C, et al. End-Stage Renal Disease After Renal Surgery in Patients with Normal Preoperative Kidney Function: Balancing Surgical Strategy and Individual Disorders at Baseline. Eur Urol. doi: 10.1016/j.eururo.2016.03.023.