Predictors of extrahepatic progression in patients with hepatocellular carcinoma receiving transarterial chemoembolization.

Even though hepatocellular carcinoma (HCC) is mainly characterized by a locoregional progression, the prognosis of some patients is burdened by the development of metastases. We aimed to identify risk factors of extrahepatic progression (EHP) in HCC patients undergoing transarterial chemoembolization (TACE). From the ITA.LI.CA database, 890 patients treated with first-line TACE were retrieved. Incidence and predictors of EHP were compared between patients with tumor burden score (TBS) ≤4.2 and >4.2 (cut-off determined by ROC curve analysis). Validation (n=442) and derivation (n=448) cohorts were used to create a predictive model for EHP after TACE (EHPaT score). During a median follow-up of 28.6 months (IQR, 14.0-50.0), 76.2% of patients showed progression after treatment. In the TBS >4.2 group, a significantly higher proportion of patients demonstrated extrahepatic spread at first progression (11.2% vs. 4.3%; p<0.001) and overall during follow-up (35.4% vs. 19.3%; p<0.001). The most common sites of metastases were lymph nodes and lung. Patients with TBS ≤4.2 had a significantly longer progression free survival (11.6 vs. 9.0 months; p<0.001) and overall survival (54.1 vs. 31.1 months; p<0.001). Independent predictors of EHP were TBS, radiological response and alpha-fetoprotein (AFP) levels. The Cox Score for the prediction of EHP (incorporating TBS, AFP, radiological response and etiology) yielded an AUROC of 0.743 (95% CI 0.656-0.830) at first progression and an AUROC of 0.701 (95% CI 0.645-0.757) overall during the follow-up in the derivation cohort. Similar results were obtained in the validation cohort. Although HCC is characterized by predominantly locoregional progression, identifying risk factors for metastases development is relevant for prognostic prediction and treatment allocation. Tumor burden, together with radiological response and AFP, has to be considered in the prediction of EHP after TACE. The EHPaT score revealed to be a useful tool in predicting of metastases development. [ABSTRACT FROM AUTHOR]