Introduction

Chronic kidney disease has significant implications on patient outcomes. Proteinuria along with glomerular filtration rate is increasing used as a marker for kidney disease. The relationship between pre-operative proteinuria and survival following nephrectomy is incompletely characterized. Herein, we evaluated the association of preoperative proteinuria with overall and cancer-specific survival in our institutional nephrectomy registry.

Methods

We identified patients with clear cell renal cell carcinoma treated for curative intent from 1995 to 2010. Patients were categorized based on KDIGO (Kidney Disease Improving Global Outcomes) 2012 guidelines. Overall and cancer-specific survivals were evaluated using Kaplan-Meier methodology. Cox proportional hazards regression models were used to assess for variables associated with overall and cancer-specific mortality.

Results

Between 1995 and 2010, 1,846 patients underwent radical or partial nephrectomy. Of these, 1,347 (73%) underwent preoperative predicted 24-hour urine protein testing. Patients with and without predicted 24-hour urine protein had no difference in overall survival (p=0.73) or cancer-specific survival (p=0.85). There were 804 (60%) patients classified with mild (<150 mg/day), 332 (25%) classified with moderate (150-500 mg/day), and 211 (16%) classified with severe proteinuria (>500 mg/day). Kaplan-Meier overall survival curves stratified by pre-operative proteinuria severity are depicted in the Figure (p<0.001). Multivariate analysis demonstrated severe proteinuria was associated with worse overall survival (HR 1.61 95%CI 1.26-2.07 p<0.001). Proteinuria level was not associated with worse cancer-specific survival.

Conclusions

Severe pre-operative proteinuria is associated with worse overall survival. During patient counseling, pre-operative proteinuria should be considered when estimating a patient&[prime]s overall health risk.

Funding

none