title: 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.
abstract: 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.
  
  
  METHODS
  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.
authors.affiliation: Department of Gastroenterology, Internal Medicine, Kitasato University East Hospital, Sagamihara, Japan.
authors.forename: Takahide
authors.initials: T
authors.lastname: Nakazawa
authors.forename: Hisashi
authors.initials: H
authors.lastname: Hidaka
authors.forename: Akitaka
authors.initials: A
authors.lastname: Shibuya
authors.forename: Wasaburo
authors.initials: W
authors.lastname: Koizumi