Cystatin C predicts renal function impairment after partial or radical tumor nephrectomy

Area of Science:

• Nephrology
• Oncology
• Surgical Pathology

Background:

• Renal cell carcinoma (RCC) treatment often involves nephrectomy, potentially impacting kidney function.
• Accurate monitoring of renal function is crucial for patients undergoing RCC surgery, especially those with initially normal kidney function.
• Traditional markers like creatinine may have limitations in reflecting early changes in glomerular filtration rate (GFR).

Purpose of the Study:

• To evaluate the predictive value of preoperative and postoperative cystatin C (CysC) for kidney function after partial (PN) or radical nephrectomy (RN) in RCC patients.
• To compare the efficacy of CysC versus creatinine in monitoring kidney function post-surgery.
• To identify predictors of new-onset chronic kidney disease (CKD) following nephrectomy.

Main Methods:

• A cohort of 195 RCC patients with preoperative eGFR > 60 ml/min/1.73m² underwent PN or RN.
• Logistic and linear regression models were used to assess CysC as a predictor of follow-up eGFR < 60 ml/min/1.73m².
• Postoperative CysC and creatinine levels were compared for kidney function estimation.

Main Results:

• Preoperative CysC (OR: 18.3) and RN (OR: 13.5) were independent predictors of reduced eGFR in follow-up; creatinine was not.
• A 0.1 mg/dl increase in preoperative CysC correlated with an estimated 5.8 ml/min/1.73m² decline in follow-up eGFR.
• A 'creatinine blind area' was observed postoperatively, where creatinine values plateaued despite rising CysC levels.

Conclusions:

• Preoperative CysC is a significant predictor of renal function impairment after RCC surgery.
• CysC demonstrates potential superiority over creatinine for monitoring kidney function in the early postoperative phase.
• These findings highlight the importance of CysC in managing kidney health in RCC patients undergoing nephrectomy.