Impact of BMI and Body Composition on First-line Systemic Treatment for Unresectable Hepatocellular Carcinoma.

Background/aim: The effects of body mass index (BMI) and body composition on the outcomes of systemic treatment for unresectable hepatocellular carcinoma (uHCC) remain unclear.

Patients and methods: In this retrospective study, patients with uHCC treated with lenvatinib (LEN) or atezolizumab+bevacizumab, were classified into high- (≥25 kg/m²) and low- (<25 kg/m²) BMI groups and evaluated for prognosis. Prognostic impact of body composition was also evaluated.

Results: Patients with a high BMI had lower skeletal mass index (SMI), subcutaneous adipose tissue index (SATI), and visceral adipose tissue index (VATI) compared to those in the low-BMI cohort. The baseline Child-Pugh scores and Barcelona Clinic Liver Cancer stages were comparable between the two cohorts. The overall survival (OS) was better in the high BMI group compared to the low BMI group (median, 913 vs. 484 days; p=0.008). SMI had a strong influence on OS. Additionally, low BMI, VATI, SATI, and visceral-to-subcutaneous fat ratio (VSR) in the LEN treatment group were associated with shorter progression-free survival (PFS).

Conclusion: Following systemic treatment for uHCC, patients with low BMI have a poor prognosis. Among anthropometric factors, low SMI is associated with poor OS. In the LEN treatment group, low VATI may impact PFS negatively.