Supplementary Material for: Cachexia Index as a Prognostic Indicator in Patients with Unresectable Hepatocellular Carcinoma Receiving Atezolizumab and Bevacizumab Therapy

Background and Aim: We investigated the association between the pretreatment cachexia index (CXI) and survival outcomes in patients with unresectable hepatocellular carcinoma (u-HCC) receiving atezolizumab plus bevacizumab (Atez/Bev).
Methods: We conducted a retrospective analysis of 195 patients with u-HCC treated with Atez/Bev from September 2020 to December 2023. The skeletal muscle mass index (SMI) was calculated by normalizing the psoas muscle area by the square of the height (cm²/m²). The CXI was defined as the SMI × serum albumin level (g/dL)/neutrophil-to-lymphocyte ratio. Propensity score matching (PSM) was applied to minimize the effect of potential confounders. Associations between CXI, overall survival (OS), and progression-free survival (PFS) were assessed.
Results: From the initial cohort, CXI cutoffs of 7.23 for males and 4.99 for females were established. PSM matched 60 pairs of patients with low and high CXI, showing no significant differences in confounding factors between groups. Kaplan-Meier analysis indicated that the low-CXI group had shorter median OS (12.5 versus 26.1 months, p = 0.009) and PFS (6.1 versus 11.1 months, p = 0.045) compared with the high-CXI group. No significant differences existed between groups in overall response rate (p = 0.994) and disease control rate (p = 0.090). Multivariate Cox proportional hazards analysis identified low CXI as an independent prognostic factor for OS (HR: 1.89, 95% CI: 1.11–3.22, p = 0.019) and PFS (HR: 1.53, 95% CI: 1.01–2.34, p = 0.047).
Conclusions: The CXI may be a valuable prognostic tool for predicting survival outcomes in patients with u-HCC receiving Atez/Bev