Prospective comparison of prognostic values of modified Response Evaluation Criteria in Solid Tumours with European Association for the Study of the Liver criteria in hepatocellular carcinoma following chemoembolisation

Backgrounds: European Association for the Study of the Liver (EASL) and modified Response Evaluation Criteria in Solid Tumours (mRECIST) guidelines, which measure changes in arterialised hepatocellular carcinoma (HCC), differ in terms of number of target lesions (all versus ≤2) and calculation method (bidimensional versus unidimensional). We compared prognostic values of mRECIST for predicting overall survival (OS) with reference to EASL criteria in treatment-naïve HCC undergoing trans-arterial chemoembolisation (TACE). Methods: The ability to predict OS during longitudinal follow-up was expressed as C-index, and a sample size of 292 patients was required to validate its equivalence between each criteria. Treatment responses were assessed using both guidelines 4 weeks after the first TACE, using dynamic computed tomography or magnetic resonance imaging. Kaplan-Meier and Cox regression analyses were used to explore differences in OS between responders (complete or partial) and non-responders (stable or progressive disease), defined by each method. Results: C-index for EASL and mRECIST guidelines was 0.753 and 0.759, respectively, demonstrating equivalence between two methods. Differences in median OS between responders and non-responders were statistically significant for both EASL (30.1 versus 18.7 months, p < 0.001) and mRECIST (33.8 versus 17.1 months, p < 0.001) guidelines. In addition to radiological response, α-fetoprotein (p < 0.001), tumour number (p < 0.001) and tumour size (p = 0.048) were significant predictors of OS. In multivariate analysis, radiological criteria, tumour number and α-fetoprotein were identified as independent predictors (all p < 0.05). Conclusion: mRECIST, a simpler method, provided prognostic values for predicting OS equivalent to EASL criteria in patients with HCC undergoing TACE as an initial treatment modality.