Tumor recurrence rate after surgery or ablation of hepatocellular carcinoma (HCC) is as high as 70%. However

there are no widely accepted adjuvant therapies; therefore

no treatment has been recommended by guidelines from the American Association for the Study of Liver Disease or the European Association for the Study of the Liver. All the registered trials failed to find any treatment to prolong recurrence-free survival

which is the primary outcome in most studies

including sorafenib. Some investigator-initiated studies revealed that anti-hepatitis B virus agents

interferon-α

transcatheter chemoembolization

chemokine-induced killer cells

and other treatments prolonged patient recurrence-free survival or overall survival after curative therapies. In this review

we summarize the current status of adjuvant treatments for HCC and explain the challenges associated with designing a clinical trial for adjuvant therapy. Promising new treatments being used as adjuvant therapy

especially anti-PD-1 antibodies

are also discussed.