Influence of skeletal muscle volume loss during lenvatinib treatment on prognosis in unresectable hepatocellular carcinoma: a multicenter study in Tohoku, Japan

Sarcopenia is associated with poor prognosis of patients with hepatocellular carcinoma (HCC). We investigated the association of skeletal muscle volume (SMV) and its change in HCC patients taking lenvatinib. In 130 HCC patients, psoas mass index (PMI) was calculated as the left–right sum of the major × minor axis of psoas muscle at the third lumbar vertebra, divided by height squared. Patients were classified into two groups (low and normal PMI) based on indices of < 6.0 cm(2)/m(2) for man and < 3.4 cm(2)/m(2) for women. Change in PMI per month during the lenvatinib administration period (ΔPMI/m) was calculated; and patients were classified into two groups (severe and mild atrophy) based on the ΔPMI/m rate, as ≥ 1% or < 1%, respectively. There was no significant difference in Overall survival (OS) between the low and normal PMI groups at the start of lenvatinib administration. OS was significantly lower in the severe atrophy group than in the mild atrophy group (median; 15.2 vs. 25.6 months, P = 0.005). Multivariate analysis revealed a significant association of severe atrophy with OS (hazard ratio 1.927, P = 0.031). Progressive loss of SMV is a strong predictor of poor prognosis in HCC patients taking lenvatinib.