Comparison of the methods for tumor response assessment in patients with hepatocellular carcinoma undergoing transarterial chemoembolization

Background & Aims: Recently, new methods, including the concept of viable enhancing tumor such as EASL and mRECIST, have been proposed for substitution of the conventional WHO and RECIST criteria in hepatocellular carcinoma (HCC) undergoing transarterial chemoembolization (TACE). Herein, we evaluated the differences of four methods and compared the association of these methods with the prognosis of HCC patients undergoing TACE. Methods: We retrospectively reviewed 114 consecutive newly diagnosed HCC patients who underwent TACE as initial treatment. We evaluated the intermethod agreement (κ values) between the methods and compared their association with the prognosis of HCC patients. Results: The κ values for EASL vs. WHO, EASL vs. RECIST, mRECIST vs. WHO, and mRECIST vs. RECIST were low, of 0.102, 0.088, 0.112, and 0.122, respectively. However, good correlations were observed for WHO vs. RECIST and EASL vs. mRECIST (κ = 0.883, κ = 0.759, respectively p <0.001). The median OS was 32.3 months. Hazard ratios (HR) for survival in responders compared with non-responders were 0.21 (95% CI; 0.12-0.37, p <0.001) for EASL and 0.27 (95% CI; 0.15-0.48, p <0.001) for mRECIST. The mean survival of responders was significantly longer than that of non-responders in both EASL (40.8 vs. 16.9 months, p <0.001) and mRECIST (41.1 vs. 20.7 months, p <0.001). In multivariate analysis, EASL response (HR 0.21, 95% CI 0.11-0.40, p <0.001) and mRECIST response (HR; 0.31, 95% CI, 0.17-0.59, p <0.001) were independently associated with survival. Conclusions: The response assessment by EASL and mRECIST could reliably predict the survival of HCC patients undergoing TACE and could be applicable in practice in preference to the conventional WHO and RECIST criteria.