Sorafenib Might Induce Sarcopenia in Patients With Hepatocellular Carcinoma by Inhibiting Carnitine Absorption.

Abstract

Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of cancers. Sorafenib, an oral multi-target TKI, improves the median overall survival time in patients with hepatocellular carcinoma (HCC). It also inhibits the absorption of carnitine by down-regulating the human organic cationic transporter OCTN2 located largely in the small intestinal mucosa and skeletal muscle. The aim of the study was to determine, by assessing carnitine metabolism, whether sarcopenia is induced in patients with HCC who are receiving sorafenib. This retrospective study included 110 adult Japanese patients with liver cirrhosis and HCC who received sorafenib. Sorafenib was administered at a dose of 200-800 mg/day for 4 weeks. Blood samples were collected before and after treatment, and serum carnitine fraction and myostatin levels were measured. Cross-sectional areas (cm2) of the skeletal muscles at the third lumbar vertebra level were determined by manually outlining computed tomography images before and after treatment. The cross-sectional areas were normalized for height [skeletal muscle index (SMI), cm2/m2]. Patients were allocated to two groups according to Child-Pugh (CP) class; 81 had CP-A liver function, and 29 had CP-B. SMI after treatment was significantly lower than that before treatment in both groups. Serum levels of total carnitine and free carnitine after treatment were significantly lower than those before treatment in both groups. There were no differences in serum levels of myostatin before and after treatment in either group. Sorafenib might decrease serum levels of carnitine by inhibiting carnitine absorption. Decreasing of serum levels of carnitine might lead to presarcopenia.