[A Case of Liver Failure Induced by Toremifene in a Patient with Metastatic Breast Cancer].

A 67-year-old woman underwent total mastectomy, postoperative radiation therapy, and adjuvant hormonal therapy more than 9 years 4 months previously. There were no symptoms of recurrence for 3.5 years after completing adjuvant hormonal therapy. A hard mass appeared on the front chest wall and was diagnosed as recurrence of breast cancer histopathologically. A computed tomography (CT) scan revealed multiple metastases in the left side of the chest wall, in the left Level Ⅱ axillary lymph nodes, and in the left lung. The patient was prescribed high-dose tremifene (HD-TOR 120 mg/day). After less than 4 months, she presented with general fatigue and yellow skin, and was admitted with grade 4 hyperbilirubinemia and grade 3 hepatic dysfunction (AST and ALT). CT and magnetic resonance imaging (MRI) showed no abnormal findings in the liver or biliary tract. Drug-induced liver injury (DILI) caused by HD-TOR was suspected and this therapy was discontinued. The liver dysfunction showed a tendency to improve with conservative treatment and the patient was discharged on the 10th day of illness. She had almost recovered after 5.5 months. A liver biopsy, a drug-lymphocyte stimulation test, and other detailed examinations were not performed, but we judged this case to be one of liver failure caused by HD-TOR-induced DILI.