Purpose: Body composition phenotypes were investigated in 200 patients with clear cell renal cell carcinoma (ccRCC), focusing on muscularity, adiposity, and fat distribution. The goal was to identify prognostic body composition features in ccRCC and their clinical correlates.
Materials and Methods: A cohort of 200 patients with resected ccRCC and available CT scans annotated by The Cancer Genome Atlas was studied. Computed tomography (CT) scans were acquired from The Cancer Imaging Archive, then a single axial image landmarked at the third lumbar vertebra (L3) was analyzed for cross sectional area and radiodensity of skeletal muscle and adipose tissue. The relationships of various body composition features with other clinical factors and with overall survival (OS) were evaluated.
Results: There were sex-related differences in body composition phenotype. High subcutaneous fat density (SFD) was uncommon in females. In males, the most common features that co-existed were low subcutaneous adipose tissue (SAT) and high SFD. In females, sarcopenia and low muscle radiodensity (myosteatosis) were the most frequently co-existent features. On univariate analysis, sarcopenia, low SAT, high SFD and myosteatosis were associated with shorter OS. On multivariate analysis, sarcopenia is associated with shorter OS (HR 1.9, P=0.05), and high SFD also associated with shorter OS (HR 2.06, P=0.04). Sarcopenia was associated with more advanced disease, but high SFD was not.
Conclusions: Body composition features in males and females with ccRCC differ significantly. Sarcopenia and increased SFD are prognostic in ccRCC. Further studies are required to understand the pathogenesis of ccRCC-associated changes in body composition.