Hepatocellular carcinoma: interventional bridging to liver transplantation

Hepatocellular carcinoma (HCC) is one of the most common solid cancers worldwide with surgery being considered the treatment of choice. However, it is limited in view of the hepatic dysfunction and high recurrence rates associated with the disease. Liver transplantation offers the advantage of both, eradicating the tumor and treating the underlying liver disease and is the only chance for cure in patients suffering from HCC. Survival is known to reach 70% after 5 years and recurrent tumor can be found in less than 20% provided transplantation is restricted to patients with single tumors < or =5 cm or three nodules <3 cm (Milan criteria). However, donor organs are limited and the time on the transplant waiting list is up to 6 or 12 months in Europe and the United States with up to 30-40% dropouts per year. It has been demonstrated that patients with untreated HCC while on the waiting list longer than 6-10 months do not have any benefit in survival after liver transplantation. Interventional treatment options such as transarterial chemoembolization and percutaneous ablation techniques documented promising results concerning the reduction of dropouts from the waiting list and the potential risk for recurrent tumor. Mortality and morbidity were considerably low when radiological interventions had been considered as bridging therapies for liver transplantation. Percutaneous therapies come along with tumoral seeding of 0.1% to 0.6%. Adjuvant treatment with TACE, PEI, and/ or RFA in T1- and T2-staged HCC resulted in tumor-free survival after transplantation of 95.2% after 4 years and intention-to-treat survival of 94%, 85%, and 79% at 1, 2, and 3 years, respectively. Aggressive ablation therapy with a short transplant waiting time has the potential to optimize the use of liver transplantation for curative intent in selected cirrhotic HCC patients. Especially combined treatments seemed to play a key role in achieving complete tumor necrosis associated with improved disease-free survival after liver transplantation. In conclusion, no evidence based data exist in the literature supporting the efficacy of adjuvant interventional treatment modalities for HCC in patients awaiting liver transplantation. However, it has been shown that adjuvant (multimodal) interventional treatments seem a promising option for safe and effective bridging.