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Partial nephrectomy preserves renal function better than radical nephrectomy for complex tumors, especially in younger patients with higher baseline eGFR.

“Complex renal masses are often defined by their size, location, and involvement of adjacent structures, making surgical decision-making more challenging,” researchers wrote in JU Open Plus. “Partial nephrectomy, a nephron-sparing approach, has emerged as the preferred option for patients with localized renal tumors, offering the potential to preserve renal function while achieving effective oncological outcomes. Nonetheless, the choice between partial and radical nephrectomy is influenced by multiple factors, including tumor complexity, patient comorbidities, and surgeon expertise.”

Wesley Justino Magnabosco, MD, and colleagues conducted a retrospective observational cohort study to examine outcomes associated with partial and radical nephrectomy in patients with complex renal masses. Analyses that considered both surgical approach and patient-related factors aimed to identify independent predictors of postoperative renal function.

In total, 378 nephrectomies were completed between 2018 and 2022, 119 of which involved complex renal masses. The median age of patients was 61 years, and pathologic staging identified the following tumor stages:

• Stage T1b tumors, n=49
• Stage T2a tumors, n=11
• Stage T2b tumors, n=7
• Stage T3a tumors, n=52

Clear cell carcinoma emerged as the predominant histologic subtype (73.9%), and most patients (90.8%) had negative surgical margins. More than half of the patients (68.9%) underwent radical nephrectomy, more commonly for stage T3a tumors, and 31.1% underwent partial nephrectomy, most often in T1b cases.

Predictors of Renal Function Over Time

Dr. Magnabosco and colleagues reported statistically significant differences in the maintenance of estimated glomerular filtration rate (eGFR), with partial nephrectomy showing greater preservation of renal function over time (P=0.01).

“Notably, some patients in the partial nephrectomy group exhibited an improvement in renal function above their preoperative baseline,” the researchers wrote. “The observed improvement in renal function, even above baseline levels in some patients, may be attributed to compensatory mechanisms and hyperfiltration in the remaining renal parenchyma. After partial nephrectomy, the remaining nephrons can increase their filtration capacity to maintain overall renal function. This compensatory response may initially result in an eGFR higher than the preoperative baseline, although long-term effects on glomerulosclerosis and renal function decline should be closely monitored.”

Age and preoperative renal function were also significant predictors of renal function over time, with patients younger than 60 years maintaining an eGFR of 60 mL/min/1.73 m² or higher more successfully (P=0.001). Patients with higher preoperative eGFR also had better postoperative outcomes (P=0.002).

Regarding surgical parameters, partial nephrectomies with ischemia times of less than 25 minutes were associated with better outcomes (P=0.028). Laparoscopic approaches had higher effectiveness than open surgeries, achieving an eGFR of 60 mL/min/1.73 m² or more in 93.8% of cases.

Multivariate analysis demonstrated that patients with a preoperative eGFR of less than 60 mL/min/1.73 m²  had a 32-fold higher risk for decline in postoperative function (P=0.001). Radical nephrectomy was associated with a nearly 4-fold greater risk for renal functional deterioration versus nephron-sparing surgery (P=0.014).

Preoperative Patient Evaluations & Future Research

“Treating complex renal masses poses a significant challenge for surgeons because it requires evaluating numerous variables to provide the best possible treatment,” Dr. Magnabosco and colleagues wrote. “Desired postoperative outcomes ideally integrate both functional and oncological aspects.”

The current study indicates that the primary factors positively impacting the evolution of renal function are age (<60), preoperative renal function (GFR, >90 mL/min/1.73 m²), partial nephrectomy, and ischemia time (<25 minutes). Further, comorbidities, initial staging, disease volume, and minimally invasive routes are “relevant factors that can lead to superior results, based on other studies,” the researchers wrote. The development of chronic kidney disease did not unfavorably impact global survival or cardiovascular complications.

“These findings support the continued emphasis on nephron-sparing strategies, even in challenging cases, and highlight the need for careful preoperative evaluation to optimize patient outcomes,” the researchers wrote. “Future prospective studies with larger cohorts and long-term follow-up are warranted to further refine surgical strategies and validate the predictive factors identified in this study.”