Parenchymal obliteration by renal masses: Functional and oncologic implications

Area of Science:

• Urology
• Oncology
• Nephrology

Background:

• Renal tumors can invade and replace normal kidney tissue.
• Substantial parenchymal volume replacement (PVR) by renal cell carcinoma (RCC) may impact oncologic outcomes.
• Previous studies on PVR are limited, necessitating further investigation with advanced methodologies.

Purpose of the Study:

• To evaluate the oncologic implications of PVR in patients with non-metastatic renal tumors.
• To utilize accurate and objective tools for quantifying PVR.
• To assess the association between PVR and patient survival outcomes.

Main Methods:

• Retrospective evaluation of 1,222 patients with non-metastatic renal tumors treated with partial or radical nephrectomy.
• Semiautomated software used for parenchymal volume analysis to estimate split renal function and preoperative volumes.
• Calculation of %PVR using contralateral kidney as a control, with patients grouped by PVR degree: minimal (<5%), modest (5%-25%), and prominent (≥25%).

Main Results:

• PVR correlated inversely with preoperative ipsilateral GFR and directly with advanced pathologic stage, high tumor grade, clear cell histology, and sarcomatoid features.
• Prominent PVR (≥25%) was associated with shortened recurrence-free, cancer-specific, and overall survival.
• Male sex, ≥pT3a stage, tumor grade 4, positive surgical margins, and PVR≥25% were independent predictors of reduced recurrence-free survival.

Conclusions:

• Obliteration of normal renal parenchyma by RCC significantly affects preoperative renal function and influences patient selection.
• Increased PVR is associated with aggressive tumor characteristics.
• Higher PVR independently predicts reduced recurrence-free survival, warranting further investigation.