Predicting Renal Function Improvement After Partial Nephrectomy

Jonathan Afari, MD, of the University of California, San Diego, and colleagues designed an analysis to better understand the factors that lead to renal function improvement after partial nephrectomy.

Results of their analysis were presented at the 2024 European Association of Urology Congress.

Partial nephrectomy is considered a viable management strategy for patients with localized renal masses. A proportion of patients experience renal function improvement post-partial nephrectomy.

To identify and characterize factors contributing to this phenomenon, Dr. Afari and colleagues conducted a retrospective, multicenter analysis of 3845 patients who underwent open or minimally invasive partial nephrectomy for renal neoplasms. They defined post-partial nephrectomy improvement as an estimated glomerular filtration rate (eGFR) at least 10% greater than preoperative baseline at last follow-up.

Descriptive and Cox regression analysis was performed to identify factors associated with improved function and noncancer mortality. A Kaplan-Meier analysis was used to determine noncancer-specific survival and compare functional improvement, GFR improvement less than an improvement of 10% to decline greater than 25%, and eGFR decline greater than 25%.

After a median follow-up of 48.2 months, improved eGFR was observed in 16.3% (n=626) of patients. Researchers reported that clear cell disease (hazard ratio [HR], 1.46; P=.038) and clampless technique (HR, 1.43; P=.018) were associated with a greater likelihood of improved eGFR.

Furthermore, they noted the following factors were associated with a decreased likelihood of improved eGFR:

• Increasing age (HR, 0.93; P=.001)
• Diabetes mellitus (HR, 0.71; P=.012)
• Minimally invasive surgery (HR, 0.76; P=.009)
• Increasing Charlson Comorbidity Index score (HR, 0.92; P=.019)
• Decreasing preoperative eGFR (HR, 0.97; P<.001)
• Increasing tumor size (HR, 0.92; P=.002)

Cox regression analysis showed increased eGFR (HR, 0.54; P=.006) and Latino and Asian ethnicity (HR, 0.41; P=.001 and P=.021, respectively) to be associated with decreased noncancer mortality. Contrarily, increasing age (HR, 1.03; P<.001), male sex (HR, 1.63; P=.002), and diabetes mellitus (HR, 1.42; P=.014) were associated with increased noncancer mortality.

The Kaplan-Meier analysis comparing renal functional improvement with GFR improvement less than an improvement of 10% to decline greater than 25%, and eGFR decline greater than 25%, revealed 5-year noncancer-specific survival of 95.5%, 96.1%, and 93.2%, respectively (P=.0001).

“A small but significant proportion of patients experience improved eGFR post-partial nephrectomy,” study authors wrote, noting that clear cell disease and clampless technique are associated with improved eGFR and that eGFR improvement is associated with decreased noncancer mortality risk.