Tumour Burden Score as a Predictor of Extrahepatic Progression After Transarterial Chemoembolization for Hepatocellular Carcinoma: An Observational Multicenter Study

Background: In patients with hepatocellular carcinoma (HCC), extrahepatic progression (EHP) has a known dismal meaning. We evaluated the incidence and risk factors of EHP in HCC patients treated with transarterial chemoembolization (TACE), and the predictive role of tumour burden. Methods: From the ITA.LI.CA database, 890 HCC patients undergoing first-line TACE were included. Tumour burden score (TBS) was calculated and, after identification of the best cut-point value, incidence and predictors of EHP were compared between TBS-low and TBS-high groups. Independent predictors of EHP at the first progression episode or at any time during follow-up were identified through multivariable Cox analysis. Results: After TACE, 7.2% of patients experienced EHP at the first progression episode, while the overall EHP rate during the follow-up was 26.1%. The best cut-point for TBS was 3.66. TBS-high group (> 3.66) showed a significantly higher proportion of EHP both at first progression (10.4% vs. 3.6%; p < 0.001) and overall (32.6% vs. 18.7%; p < 0.001) compared to the TBS-low group. Moreover, TBS-high patients had shorter progression-free survival and overall survival. TBS-high and AFP levels emerged as independent predictors of EHP at the first progression episode and during the follow-up, and their combined evaluation accurately stratified patients for their risk of EHP. Conclusion: Extrahepatic dissemination is infrequent in HCC patients treated with TACE. TBS is easily calculable and helps in identifying patients at higher risk of metastasis development.