Parenchymal obliteration by renal masses: Functional and oncologic implications

Akira Kazama; Carlos Munoz-Lopez; Worapat Attawettayanon; Melissa Boumitri; Eran Maina; Zaeem Lone; Nityam Rathi; Kieran Lewis; Rebecca A Campbell; Diego Aguilar Palacios; Jihad Kaouk; Georges-Pascal Haber; Samuel Haywood; Nima Almassi; Christopher J Weight; Erick M Remer; Ryan Ward; Amy S Nowacki; Steven C Campbell

doi:10.1016/j.urolonc.2024.04.019

Parenchymal obliteration by renal masses: Functional and oncologic implications

Urol Oncol. 2024 May 9:S1078-1439(24)00439-3. doi: 10.1016/j.urolonc.2024.04.019. Online ahead of print.

Authors

Akira Kazama¹, Carlos Munoz-Lopez², Worapat Attawettayanon³, Melissa Boumitri², Eran Maina², Zaeem Lone², Nityam Rathi², Kieran Lewis², Rebecca A Campbell², Diego Aguilar Palacios², Jihad Kaouk², Georges-Pascal Haber², Samuel Haywood², Nima Almassi², Christopher J Weight², Erick M Remer⁴, Ryan Ward⁴, Amy S Nowacki⁵, Steven C Campbell⁶

Affiliations

¹ Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH; Department of Urology, Molecular Oncology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
² Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH.
³ Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH; Division of Urology, Department of Surgery, Faculty of Medicine, Songklanagarind Hospital, Prince of Songkla University, Songkhla, Thailand.
⁴ Imaging Institute, Cleveland Clinic, Cleveland OH.
⁵ Department of Quantitative Sciences, Cleveland Clinic, Cleveland, OH.
⁶ Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH. Electronic address: campbes3@ccf.org.

PMID: 38729867
DOI: 10.1016/j.urolonc.2024.04.019

Abstract

Objectives: Most renal tumors merely displace nephrons while others can obliterate parenchyma in an invasive manner. Substantial parenchymal volume replacement (PVR) by renal cell carcinoma (RCC) may have oncologic implications; however, studies regarding PVR remain limited. Our objective was to evaluate the oncologic implications associated with PVR using improved methodology including more accurate and objective tools.

Patients/methods: A total of 1,222 patients with non-metastatic renal tumors managed with partial nephrectomy (PN) or radical nephrectomy (RN) at Cleveland Clinic (2011-2014) with necessary studies were retrospectively evaluated. Parenchymal volume analysis via semiautomated software was used to estimate split renal function and preoperative parenchymal volumes. Using the contralateral kidney as a control, %PVR was defined: (parenchymal volume_{contralateral}-parenchymal volume_ipsilateral) normalized by parenchymal volume_{contralateral} x100%. PVR was determined preoperatively and not altered by management. Patients were grouped by degree of PVR: minimal (<5%, N = 566), modest (5%-25%, N = 414), and prominent (≥25%, N = 142). Kaplan-Meier was used to evaluate survival outcomes relative to degree of PVR. Multivariable Cox-regression models evaluated predictors of recurrence-free survival (RFS).

Results: Of 1,122 patients, 801 (71%) were selected for PN and 321 (29%) for RN. Overall, median tumor size was 3.1 cm and 6.8 cm for PN and RN, respectively, and median follow-up was 8.6 years. Median %PVR was 15% (IQR = 6%-29%) for patients selected for RN and negligible for those selected for PN. %PVR correlated inversely with preoperative ipsilateral GFR (r = -0.49, P < 0.01) and directly with advanced pathologic stage, high tumor grade, clear cell histology, and sarcomatoid features (all P < 0.01). PVR≥25% associated with shortened recurrence-free, cancer-specific, and overall survival (all P < 0.01). Male sex, ≥pT3a, tumor grade 4, positive surgical margins, and PVR≥25% independently associated with reduced RFS (all P < 0.02).

Conclusions: Obliteration of normal parenchyma by RCC substantially impacts preoperative renal function and patient selection. Our data suggests that increased PVR is primarily driven by aggressive tumor characteristics and independently associates with reduced RFS, although further studies will be needed to substantiate our findings.

Keywords: Aggressive pathologic features; Parenchymal volume analysis; Parenchymal volume replacement; Partial nephrectomy; Radical nephrectomy; Renal cell carcinoma.