Effect of sex-specific abdominal fat tissue composition on WHO/ISUP nuclear grade of clear cell renal cell carcinoma

Background/aim: To investigate the relationship between sex-related visceral obesity and WHO/ISUP nuclear grade in clear cell renal cell carcinoma (ccRCC). Materials and methods: Between January 2018 and June 2022, 95 patients (56 men and 39 women) with pathologically proven ccRCC who underwent abdominal computed tomography examination were retrospectively examined. The patients were classified into two groups: low- and high-WHO/ISUP nuclear grade ccRCC (n = 58 and n = 37), respectively. Patient height, weight, body mass index (BMI), sex, age, subcutaneous fat area (SFA), visceral fat area (VFA), total fat area (TFA), and percentage of visceral fat (VF%) were recorded for the two groups. Results: No significant differences were found in age, BMI, SFA, or TFA, but VFA and VF% were significantly higher in the high-grade patient group. In males, maximal tumor diameter (MTD) (67.8% sensitivity and 76.9% specificity) had the highest area under the curve (AUC), while in females, VF% (70.0% sensitivity and 73.7% specificity) had the highest AUC. VF% revealed an odds ratio (OR) of 1.09 in females with high-grade ccRCC, and in males, MTD was an independent predictor of ccRCC with an OR of 1.03. Conclusions: Sex-related body fat tissue, including VFA and VF%, could be used for estimating WHO/ISUP nuclear grade in patients with ccRCC, especially in females.