Preoperative proteinuria as a novel biomarker for predicting postoperative renal insufficiency after nephrectomy for renal cell carcinoma: a systematic review and meta-analysis.

Background: Identifying reliable predictors of postoperative renal insufficiency (PRI) following partial or radical nephrectomy for renal cell carcinoma (RCC) is critical for optimizing perioperative management.

Methods: We systematically searched MEDLINE, Cochrane Library, and Embase up to March 20, 2025, to identify cohort studies that evaluated the association between preoperative proteinuria and PRI. We calculated pooled odds ratios (ORs) with 95% confidence intervals (CIs) using a random-effects model. Subgroup analyses were stratified by study design (prospective vs. retrospective) and surgical modality (partial vs. radical nephrectomy).

Results: Six cohort studies involving 3124 patients were included. Preoperative proteinuria was significantly associated with an increased risk of PRI (OR = 2.69, 95% CI 1.48-4.89; I² = 67.3%). We found that retrospective studies showed a stronger association between preoperative proteinuria and PRI (OR = 3.35, 95% CI 1.71-6.56) compared to prospective studies (OR = 1.89, 95% CI 0.98-3.66). Subgroup analysis by surgical approach revealed significant risk elevation in both partial nephrectomy (OR = 2.11, 95% CI 1.34-3.33) and radical nephrectomy cohorts (OR = 5.50, 95% CI 4.31-7.02), with a notably higher effect size in the latter.

Conclusion: Preoperative proteinuria is significantly associated with an elevated risk of PRI in patients undergoing nephrectomy for renal cell carcinoma. These findings emphasize the need to incorporate proteinuria assessment into preoperative risk evaluations to improve patient counselling and perioperative management. Future high-quality prospective studies, particularly multicenter investigations with standardized protocols, are essential to confirm these associations and explore the pathophysiological mechanisms underlying proteinuria-related renal functional decline.