Complete response by vitamin K2 analog monotherapy in sorafenib-failure advanced hepatocellular carcinoma: A case report.

There have been reports that a vitamin K2 (VK2) analog is beneficial for the prevention of recurrence in hepatocellular carcinoma (HCC) patients after curative therapy. However, the VK2 analogs in current use do not appear to show dramatic antitumor effects when given alone. Here, we report the case of a 67-year-old male patient with sorafenib-failure advanced HCC who achieved complete response (CR) after VK2 analog monotherapy. At the time of sorafenib failure confirmation, the patient had multiple intrahepatic tumors, multiple lung metastases, and Vp3 portal vein tumor thrombosis. He had poor liver function (Child-Pugh score of 9, Child-Pugh class B) and poor performance status (Eastern Cooperative Oncology Group performance status 2). Both serum α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) levels were elevated (558 900 ng/mL and 917 300 mAU/mL, respectively). Treatment with VK2 analog was initiated at 45 mg/day. Five months later, both tumor markers had decreased to normal levels (AFP 8 ng/mL and DCP 10 mAU/mL). Contrast-enhanced computed tomography showed that all intrahepatic tumors had shrunk, there was no enhancement of tumor staining in the arterial phase, and all lung metastases and portal vein tumor thromboses had disappeared. We considered that CR was achieved according to the modified Response Evaluation Criteria in Solid Tumors. Eighteen months after the start of VK2 analog administration, the patient continues to receive treatment and has remained in CR without adverse events. Here, we report a rare case of sorafenib-failure advanced HCC in which sustained CR was achieved by VK2 analog monotherapy.