Efficacy of Selective Transarterial Chemoembolization in Inducing Tumor Necrosis in Small (<5 cm) Hepatocellular Carcinomas

Transarterial chemoembolization (TACE) is commonly used as a bridge therapy for patients awaiting liver transplantation (LT) and for downstaging patients initially not meeting the Milan criteria. The primary aim of this study was to analyze whether a difference exists between selective/superselective and lobar TACE in determining tumor necrosis by a pathological analysis of the whole lesion at the time of LT. The secondary aim was to investigate the relationship between the tumor size and the capacity of TACE to induce necrosis. Data were extracted from a prospective database of 67 consecutive patients who underwent LT for hepatocellular carcinoma and cirrhosis from 2003 to 2009 and were treated exclusively with TACE as a bridging (n = 53) or downstaging therapy (n = 14). We identified 122 nodules; 53.3% were treated with selective/superselective TACE. The mean histological necrosis level was 64.7%; complete tumor necrosis was obtained in 42.6% of the nodules. In comparison with lobar TACE, selective/superselective TACE led to significantly higher mean levels of necrosis (75.1% versus 52.8%, P = 0.002) and a higher rate of complete necrosis (53.8% versus 29.8%, P = 0.013). A significant direct relationship was observed between the tumor diameter and the mean tumor necrosis level (59.6% for lesions < 2 cm, 68.4% for lesions of 2.1-3 cm, and 76.2% for lesions > 3 cm). Histological necrosis was maximal for tumors > 3 cm: 91.8% after selective/superselective TACE and 66.5% after lobar procedures. Independent predictors of complete tumor necrosis were selective/superselective TACE (P = 0.049) and the treatment of single nodules (P = 0.008). Repeat sessions were more frequently needed for nodules treated with lobar TACE (31.6% versus 59.3%, P = 0.049). Conclusion: Selective/superselective TACE was more successful than lobar procedures in achieving complete histological necrosis, and TACE was more effective in 3- to 5-cm tumors than in smaller ones. (HEPATOLOGY 2011;53:1580-1589)