Impact of more detailed categorization of shrinkage or progression ratio at initial imaging response after sorafenib treatment in advanced hepatocellular carcinoma patients

BACKGROUND: Sorafenib therapy improves survival in unresectable hepatocellular carcinoma (HCC) patients without an objective response. The present study investigated whether the initial imaging response might be a prognostic indicator after administration of sorafenib therapy in HCC patients. PATIENTS AND METHODS: This retrospective study reviewed unresectable HCC patients undergoing sorafenib therapy. Patients evaluated without complete response, partial response (PR), or progressive disease (PD) at the initial imaging response evaluation by modified Response Evaluation Criteria in Solid Tumors were divided into three groups according to more detailed categorization of the shrinkage/progression ratio in initial imaging response. A comparison of progression-free and overall survival among these groups was performed. RESULTS: Of the 43 non-PR non-PD patients with target lesions, ten (23.3%) exhibited mild response (MR; −30% to −5%), 14 (32.6%) exhibited no change (NC; −5% to +5%), and 19 (44.2%) exhibited mild-PD (MPD; +5% to +20%). There was no statistical difference in progression-free or overall survival between MR and NC patients. The median progression-free survivals in NC+MR and mild-PD patients were 15.0 and 5.3 months, respectively (P<0.01), and the median survival times were 31.9 and 17.1 months, respectively (P<0.001). In multivariate analysis, etiology (hepatitis C virus) and initial imaging response (MR+NC) was identified as an independently good prognostic factor. CONCLUSION: More detailed categorization of shrinkage or progression at the initial imaging response evaluation may be a useful marker for predicting sorafenib treatment outcomes in HCC patients. If the initial imaging response is not progression but stability, sorafenib may have a survival benefit.