Liver transplantation for hepatocellular carcinoma on cirrhosis: strategies to avoid tumor recurrence.

Hepatocellular carcinoma (HCC) is one of the most frequent neoplasms worldwide and in most cases it is associated with chronic liver disease. Liver transplantation (LT) is potentially the optimal treatment for those patients with HCC who have a poor functional hepatic reserve due to their underlying chronic liver disease. However, due to the limited availability of donors, only those patients whose oncologic profile is favorable can be considered for LT. Despite the careful selection of candidates based on strict rules, 10 to 20% of liver transplant recipients who have HCC in the native cirrhotic liver develop tumor recurrence after transplantation. The selection criteria presently employed to minimize the risk of recurrence are based on gross tumor characteristics defined by imaging techniques; unfortunately, the accuracy of imaging is far from being optimal. Furthermore, microscopic tumor features that are strictly linked with prognosis can not be assessed prior to transplantation. Pre-transplantation tumor downstaging may allow transplantation in patients initially outside the selection criteria and seems to improve the prognosis; it also provides information on tumor biology. The main peculiarity of the transplantation setting, when this is compared with other modalities of treatment, is the need for pharmacological immunosuppression: this is based on drugs that have been demonstrated to increase the risk of tumor development. As HCC is an aggressive malignancy, immunosuppression has to be handled carefully in patients who have HCC at the time of transplantation and new categories of immunosuppressive agents should be considered. Adjuvant chemotherapy following transplantation has failed to show any significant advantage. The aim of the present study is to review the possible strategies to avoid recurrence of HCC after liver transplantation based on the current clinical evidence and the more recent developments and to discuss possible future directions.