Prognostic value of CT-defined sarcopenic obesity in hepatocellular carcinoma patients undergoing transarterial chemoembolization

PURPOSE: The prognostic value of sarcopenic obesity is controversial in hepatocellular carcinoma (HCC) patients undergoing transarterial chemoembolization (TACE). This study aimed to deconstruct the sarcopenic obesity phenotype to clarify the independent prognostic impacts of sarcopenia and visceral obesity. METHODS: We retrospectively analyzed 415 patients with unresectable HCC who underwent TACE between 2009 and 2020. Skeletal muscle index (SMI) and visceral fat area (VFA) were measured from baseline CT scans at the L3 vertebra level. Sarcopenia (SMI ≤ 36.2 cm²/m² in males, ≤ 29.6 cm²/m² in females) and visceral obesity (VFA ≥ 100 cm²) were defined using Asian-specific cutoffs. Overall survival (OS) was analyzed using Kaplan-Meier and Cox proportional hazards models, with sex-stratified analysis. RESULTS: Among 415 patients (72% male, median follow-up 21.4 months), sarcopenia prevalence was 34% and visceral obesity 59%. In sex-stratified analysis, sarcopenia predicted mortality in males and reduced the median OS by 11 months (14.4 vs. 25.4 months, p < 0.001), but not in females (23.4 vs. 22.8 months, p = 0.900). Visceral obesity showed no prognostic impact in either sex. In sex-stratified multivariate analysis adjusting for Child-Pugh class, tumor burden, BCLC stage, and AFP, sarcopenia remained independently associated with mortality in males (adjusted hazard ratio [HR] = 1.41, 95% CI: 1.06-1.86, p = 0.018) but not in females (adjusted HR = 0.84, 95% CI: 0.55-1.27, p = 0.404; p for interaction = 0.070), while visceral obesity and sarcopenic obesity composite showed no prognostic value in either sex. CONCLUSION: The sarcopenic obesity composite phenotype lacks prognostic value in TACE-treated HCC patients. Sarcopenia independently predicts mortality in males but not females, while visceral obesity shows no independent prognostic significance. Clinical risk stratification could consider sarcopenia assessment in male patients rather than composite phenotypes.