Comparison of systems for assessment of post-therapeutic response to sorafenib for hepatocellular carcinoma

To test the hypothesis that use of the response evaluation criteria in cancer of the liver (RECICL), an improved evaluation system designed to address the limitations of the response evaluation criteria in solid tumors 1.1 (RECIST1.1) and modified RECIST (mRECIST), provides for more accurate evaluation of response of patients with hepatocellular carcinoma (HCC) to treatment with sorafenib, a molecularly targeted agent, as assessed by overall survival (OS). The therapeutic response of 156 patients with advanced HCC who had been treated with sorafenib therapy for more than 1 month was evaluated using the RECIST1.1, mRECIST, and RECICL. After categorization as showing progressive disease (PD), stable disease (SD), or objective response, the association between OS and categorization was examined using the Kaplan-Meier method to develop survival curves. The 141 cases categorized as PD or SD by the RECIST1.1, but objective response by the mRECIST and RECICL, were further analyzed for determination of the association between OS and categorization. Only categorization using the RECICL was found to be significantly correlated with OS (p = 0.0033). Among the patients categorized as SD or PD by the RECIST1.1, reclassification by the RECICL but not the mRECIST was found to be significantly associated with OS and allowed for precise prediction of prognosis (p = 0.0066). Only the use of the RECICL allowed for identification of a subgroup of HCC patients treated with sorafenib with improved prognosis. The RECICL should, therefore, be considered a superior system for assessment of therapeutic response.