The Potential of Visceral Adipose Tissue in Distinguishing Clear Cell Renal Cell Carcinoma from Renal Angiomyolipoma with Minimal Fat

Abstract

Purpose

To overcome the challenge of preoperative differentiation between clear cell renal cell carcinoma (ccRCC) and renal angiomyolipoma with minimal fat (RMFAML), we evaluated the potential of visceral adipose tissue (VAT) in distinguishing RMFAML from ccRCC.

Patients and Methods

Patients (191) were divided into ccRCC and RMFAML groups according to postoperative pathology. Umbilical horizontal computed tomography (CT) images were used for visceral fat area (VFA), subcutaneous fat area (SFA) and total fat area (TFA) measurements. Logistic regression was used to identify risk factors for ccRCC. Areas under the receiver operating characteristic (ROC) curve (AUCs) were compared to identify the most valuable indicator for identifying ccRCC and RMFAML.

Results

In total, 166 patients had ccRCC, and 25 had RMFAML. ccRCC and RMFAML patients showed significant differences in age (P<0.001), sex (P<0.001), hypertension (P=0.027), BMI (P<0.001), SFA (P=0.046), VFA (P<0.001) and TFA (P<0.001). According to multiple logistic regression analysis, male sex [4.311 (1.469~12.653), p=0.008]; older age [1.047 (1.008~1.088), p=0.017]; and higher BMI [1.305 (1.088~1.566), p=0.004], SFA [1.013 (1.003~1.023), p=0.008], VFA [1.026 (1.012~1.041), p<0.001] and TFA [1.011 (1.005~1.017), p=0.001] were associated with ccRCC. The AUCs of sex (male), age, BMI, TFA, VFA, and SFA were 0.726, 0.687, 0.783, 0.769, 0.840, and 0.645, respectively. The VFA cut-off value was 69.99 cm². The sensitivity and specificity of higher VFA (≥69.99 cm²) for ccRCC diagnosis were 79.52% and 80.00%, respectively.

Conclusion

In differentiating ccRCC from RMFAML, male sex, older age, and higher BMI, TFA, SFA, and VFA are risk factors for ccRCC. VFA is the most effective indicator for identifying ccRCC.

Keywords:

• body mass index
• clear cell renal cell carcinoma
• obesity-related index
• renal angiomyolipoma with minimal fat
• visceral adipose tissue
• visceral fat area

Abbreviations

AUC, area under the curve; BMI, body mass index; ccRCC, clear cell renal cell carcinoma; CT, computed tomography; AML, renal angiomyolipoma; RMFAML, renal angiomyolipoma with minimal fat; RCC, renal cell carcinoma; SAT, subcutaneous adipose tissue; SFA, subcutaneous fat area; ROC, receiver operating characteristic; TFA, total fat area; VAT, visceral adipose tissue; VFA, visceral fat area.

Ethics Statement

The protocol for this research project was approved by a suitably constituted ethics committee of the institution, the Committee of the First Affiliated Hospital of Soochow University (Approval No. 2015138), and the project conformed to the provisions of the Declaration of Helsinki. Informed consent was obtained from all of the subjects. Animal studies: N/A.

Disclosure

The authors report no conflicts of interest in this work.