Renal cell carcinoma (RCC), accounting for 90% of adult renal malignancies, has shown a rising incidence worldwide. Obesity is a well-established risk factor for RCC, and emerging evidence indicates that perirenal fat, a part of visceral adipose tissue (VAT), may influence tumor biology. This study aims to evaluate the predictive value of adipose tissue parameters, derived from computed tomography (CT) imaging, for determining the histologic grade and clinical stage of RCC.

Data from patients diagnosed with RCC between April 2014 and December 2020 were retrospectively analyzed. The study focused on adipose tissue parameters, including subcutaneous fat thickness (SC), subcutaneous fat area (SFA), posterior perirenal fat thickness (PFT-P), lateral perirenal fat thickness (PFT-L), and their respective ratios to body mass index (BMI). Logistic regression models were employed to evaluate the associations between these adipose tissue metrics and both tumor grade and clinical stage.

A total of 97 patients were included in the analysis. High-grade tumors (grades 3 and 4) were associated with lower SFA to BMI (SFA/BMI) ratios compared to low-grade tumors (grades 1 and 2). Advanced-stage tumors (stages 3 and 4) demonstrated reduced SFA/BMI ratios, SFA, and SC compared to early-stage tumors (stages 1 and 2). Additionally, higher-stage tumors (stages 2, 3, and 4) were characterized by decreased PFT-P, PFT-L, SFA, SFA/BMI ratio, and PFT-L to BMI (PFT-L/BMI) ratio compared to stage 1 tumors. The SFA/BMI ratio emerged as the most consistent CT-derived adipose tissue parameter for differentiating tumors of higher grade and stage.

The findings suggest that CT-derived adipose tissue parameters, particularly the SFA/BMI ratio, may serve as valuable predictors for both the histologic grade and clinical stage of RCC. These parameters could potentially be used in clinical practice to enhance preoperative risk stratification and inform patient management strategies, particularly in cases involving higher- grade and advanced-stage RCC.