Preoperative Proteinuria and Postoperative Renal Function After Partial Nephrectomy
Overview
This study evaluated the impact of preoperative proteinuria on renal function outcomes following partial nephrectomy (PN) for renal cell carcinoma (RCC). While patients with preoperative proteinuria had lower baseline renal function and higher rates of baseline CKD stage III or higher, proteinuria was not an independent predictor of postoperative renal function decline or development of CKD at long-term follow-up.
Background
Renal cell carcinoma incidence is rising, particularly among the elderly, with surgery being the primary treatment for localized disease. Preservation of renal function is critical, especially in patients with baseline renal impairment who face higher mortality risks. Proteinuria is a known risk factor for progression to end-stage renal disease and cardiovascular mortality, but its role in predicting renal outcomes after nephrectomy remains unclear. This study investigates the association between preoperative proteinuria and postoperative renal function after PN for RCC.
Data Highlights
Characteristic
Proteinuria Present (n=22)
Proteinuria Absent (n=273)
p-value
Baseline eGFR (mean ± SD)
70.1 ± 30.9 ml/min/1.73m2
88.1 ± 19 ml/min/1.73m2
0.94
Baseline CKD Stage III or higher
31.8% (7/22)
5.1% (14/273)
<0.001
De novo CKD Stage III or higher after PN
40% (6/15)
42.8% (111/259)
>0.99
Regression coefficient for eGFR decline
−0.51
−0.35
0.6
Key Findings
Preoperative proteinuria was present in 7.4% of patients undergoing PN for RCC.
Patients with proteinuria had significantly higher rates of baseline CKD stage III or higher (31.8% vs 5.1%, p < 0.001).
Mean baseline eGFR was similar between groups (70.1 vs 88.1 ml/min/1.73m2, p = 0.94), but proteinuria patients had lower absolute values.
Postoperative renal function decline rates did not differ significantly between patients with and without preoperative proteinuria (p = 0.6).
Preoperative proteinuria was associated with de novo CKD stage III or higher at 12 months on univariate analysis (OR 3.2, p = 0.005) but was not an independent predictor on multivariable analysis.
Lower baseline eGFR was the only independent predictor of postoperative CKD stage III or higher at both 12 months and last follow-up.
Clinical Implications
Preoperative proteinuria identifies patients with higher baseline renal impairment but does not independently predict long-term renal function decline after partial nephrectomy. Baseline eGFR remains the most reliable predictor for postoperative CKD risk. Clinicians should continue to assess baseline renal function comprehensively when counseling patients and planning nephron-sparing surgery.
Conclusion
Preoperative proteinuria correlates with baseline renal impairment but is not an independent predictor of postoperative renal function decline following partial nephrectomy for RCC. Baseline eGFR should guide risk stratification and postoperative management.
References
Increasing RCC incidence and surgery as mainstay treatment
Proteinuria as a risk factor for ESRD and cardiovascular mortality
Association of preoperative proteinuria with mortality after nephrectomy
CKD and cardiovascular risk in high-income countries
