Sarcopenia, intramuscular fat deposition, and visceral adiposity independently predict the outcomes of hepatocellular carcinoma

TLDR

Obesity and underweight both increase hepatocellular carcinoma risk, but body composition rather than BMI appears to drive prognosis. The study aimed to determine whether skeletal muscle, intramuscular fat, and visceral adiposity measured by CT predict HCC outcomes. CT-derived skeletal muscle index, mean muscle attenuation, visceral and subcutaneous adipose indices, and visceral‑to‑subcutaneous ratios were quantified in 1,257 HCC patients to assess their prognostic value. Low skeletal muscle index, low muscle attenuation, and high visceral‑to‑subcutaneous ratio independently predicted mortality (HRs 1.52, 1.34, 1.35), whereas BMI did not.

Abstract

Obesity defined by body mass index (BMI) significantly increases the risk of hepatocellular carcinoma (HCC). In contrast, not only obesity but also underweight is associated with poor prognosis in patients with HCC. Differences in body composition rather than BMI were suggested to be true determinants of prognosis. However, this hypothesis has not been demonstrated conclusively.We measured skeletal muscle index (SMI), mean muscle attenuation (MA), visceral adipose tissue index, subcutaneous adipose tissue index, and visceral to subcutaneous adipose tissue area ratios (VSR) via computed tomography in a large-scale retrospective cohort of 1257 patients with different stages of HCC, and comprehensively analyzed the impact of body composition on the prognoses.Among five body composition components, low SMI (called sarcopenia), low MA (called intramuscular fat [IMF] deposition), and high VSR (called visceral adiposity) were significantly associated with mortality, independently of cancer stage or Child-Pugh class. A multivariate analysis revealed that sarcopenia (hazard ratio [HR], 1.52; 95% confidence interval [CI], 1.18-1.96; p=0.001), IMF deposition (HR, 1.34; 95% CI, 1.05-1.71; p=0.020), and visceral adiposity (HR, 1.35; 95% CI, 1.09-1.66; p=0.005) but not BMI were significant predictors of survival. The prevalence of poor prognostic body composition components was significantly higher in underweight and obese patients than in normal weight patients.Sarcopenia, IMF deposition, and visceral adiposity independently predict mortality in patients with HCC. Body composition rather than BMI is a major determinant of prognosis in patients with HCC.