Impact of interferon therapy after curative treatment of hepatocellular carcinoma

Primary and secondary prevention of hepatocellular carcinoma (HCC) which has become endemic worldwide in recent years are the most important issues in reducing mortality of HCC patients. Among several compounds previously reported for secondary prevention, treatment with interferon (IFN) is widely applied and shows encouraging results. To date, there have been 8 published randomized control trials (RCTs) and 6 published non-RCTs on IFN therapy after curative treatment of HCCs. Positive results were shown in 6 of 8 RCTs and in all of 6 non-RCT cohort studies regarding either recurrence rate or patient survival. The impact of IFN therapy after curative treatment of HCC can be summarized as follows: (1) HCC incidence of recurrence is reduced through viral clearance or long-term IFN treatment, even though HCV is not cleared. (2) Low-dose, long-term IFN (maintenance) therapy may suppress HCC recurrence through direct action of IFN on tumor cells. (3) Patient survival is improved through growth inhibition of recurrent tumors, as well as preservation of liver function. (4) According to the above 3 points, there is more chance to receive curative treatment in the IFN than the non-IFN group. (5) Pegylated IFN (PEG-IFN) may be more beneficial than non-PEG-IFN products since IFN concentration is maintained in the body at a high level, which is favorable for its action as a direct anticancer agent. (6) It may be concluded that IFN treatment after curative treatment of HCC is beneficial at least in HCV-related HCC, since it lowers recurrence and improves survival.