Visceral fat measured with CT helps predict recurrence-free survival in patients with localized clear cell renal cell carcinoma

Abstract

Background: To investigate the prognostic significance of visceral fat to predict recurrence-free survival in patients with localized clear cell renal cell carcinoma (ccRCC).

Methods: This study included patients with localized ccRCC who had undergone curative surgery. Visceral, subcutaneous fat and the relative visceral fat area (rVFA) were quantified utilizing preoperative CT images. The association between rVFA and recurrence-free survival (RFS) was explored using restricted cubic splines, Cox proportional hazards regression, and Kaplan-Meier survival analysis. The predictive capability of rVFA was evaluated using the Boruta algorithm, a predictive model was developed using the random survival forest (RSF) with results visualized via Shapley additive explanations (SHAP).

Results: Four hundred and forty six patients were included. The follow-up median duration was 48.5 months, during which 57 patients experienced metastasis or death. Restricted cubic spline model revealed a nonlinear association between rVFA and tumor progression, exhibiting a U-shaped curve trend with an inflection point at 0.40. Beyond this threshold, rVFA was significantly correlated with an increased risk of progression. The RSF model yielded an area under the curve (AUC) of 0.89 for predicting 1-year RFS, 0.73 for 3-year RFS, and 0.75 for 5-year RFS. Both Boruta and SHAP analyses identified rVFA as a significant predictive feature.

Conclusions: A U-shaped association between rVFA and risk of tumor recurrence was observed among patients with ccRCC. A high rVFA is significantly correlated with an increased risk of adverse events, thus indicating that rVFA is a potential indicator for predicting the prognosis of ccRCC.

Keywords: Clear cell renal cell carcinoma (ccRCC); Recurrence-free survival (RFS); Relative visceral fat area (rVFA).