Supplementary Material for: Relationship of atezolizumab plus bevacizumab treatment with muscle volume loss in unresectable hepatocellular carcinoma patients– multicenter analysis

Background/Aim: There is no known report regarding the relationship of atezolizumab plus bevacizumab (Atez/Bev) treatment with muscle volume loss (MVL) in unresectable hepatocellular carcinoma (u-HCC) patients. This study aimed to elucidate the clinical relationship between MVL and Atez/Bev. Materials/Methods: From September 2020 to December 2021, 229 u-HCC patients treated with Atez/Bev and with muscle volume data obtained by computed tomography at the baseline available were analyzed (median age, 74 years; males, 186 (81.2%); ECOG PS 0/1, 221 (96.5%); HCV:HBV:alcohol:others=81:33:40:75; Child-Pugh A, 212 (92.6%); mALBI grade 1:2a:2b=79:60:90; BCLC 0:A:B:C =1:24:87:117; median observation period, 6.8 months). Japan Society of Hepatology criteria were used for definition of MVL and prognostic factors were retrospectively evaluated. Results: Multivariate Cox-hazard analysis of prognostic factors for progression-free survival (PFS) showed elevated alpha-fetoprotein (AFP) (≥100 ng/mL) (HR 1.848, 95%CI 1.264-2.702, P=0.002), modified albumin-bilirubin (mALBI) grade (≥2a) (HR 1.563, 95%CI 1.035-2.359, P=0.034), and MVL (HR 1.479, 95%CI 1.020-2.144, P=0.039) as significant factors. For overall survival (OS), significant factors included elevated AFP (≥100 ng/mL) (HR 3.564, 95%CI 1.856-6.844, P<0.001), mALBI grade (≥2a) (HR 3.451, 95%CI 1.580-7.538, P=0.002), and MVL (HR 2.119, 95%CI 1.150-3.904, P=0.016). Patients with MVL (MVL group, n=91) showed worse PFS than those without (non-MVL group, n=138) (median PFS 5.3 vs. 7.6 months, P=0.025), while the MVL group showed worse OS (P=0.038), though neither reached the median survival time. Conclusion: MVL may be a clinical factor related to poor prognosis in patients receiving Atez/Bev treatment for u-HCC.