Rapid Regression of Advanced Hepatocellular Carcinoma Associated with Elevation of Des-Gamma-Carboxy Prothrombin after Short-Term Treatment with Sorafenib – A Report of Two Cases

BACKGROUND Sorafenib is the first molecular-targeted agent that is effective for advanced hepatocellular carcinoma (HCC), with prolongation of survival. However, a complete response is very rare, and rapid regression of HCC after short-term treatment with sorafenib has not been reported previously. CASE REPORTS We describe 2 patients with advanced multiple HCC who received sorafenib for short periods of 1 or 2 weeks, respectively. Longer treatment was precluded by the development of hepatic failure as an adverse event of sorafenib. RESULTS HCC rapidly regressed, and both patients had a partial response (PR), despite short-term treatment. Furthermore, an early elevation of des-gamma-carboxy prothrombin (DCP) was temporarily seen in both patients, with no elevation of alpha-fetoprotein. CONCLUSIONS Sorafenib can induce rapid regression of advanced HCC even after short-term treatment, and the initial response of HCC was identical in both patients. Since early elevation of DCP was observed in our patients with PR, DCP might be a predictive biomarker of anti-tumor response. Further studies are required to clarify the mechanisms underlying the effectiveness of sorafenib, including the alteration of DCP.