Abstract:Background: To evaluate cost-effectiveness of adjuvant interferon therapy used with surgical resection of hepatitis C-related primary hepatocellular carcinoma. Design: We constructed a Markov model that simulated adjuvant interferon therapy after resection of hepatitis C-related hepatocellular carcinoma, and evaluated life expectancy, costs, and cancer recurrence. The reference case is a 60–year-old man with hepatitis C-related compensated cirrhosis. Results: At the baseline, adjuvant interferon therapy yielded 6.1 life years with a cost of $77, 000, and an incremental cost-effectiveness ratios of $ 15, 700/life year compared with no interferon therapy. The proportion of patients who experienced recurrence of hepatocellular carcinoma until death was reduced from 87.6% to 62.9% using adjuvant interferon therapy. The incidence of recurrent hepatocellular carcinoma after interferon influenced the cost-effectiveness of adjuvant interferon therapy. A threshold analysis showed that adjuvant interferon therapy was not cost-effective (ICER = $ 27, 000/year) if the annual incidence of recurrent hepatocellular carcinoma after interferon is 16% (baseline 8.9%). The proportions of patients with recurrent hepatocellular carcinoma were 74.4% and 86.9% at the annual recurrence rates after interferon of 16% and 35%, respectively. Conclusions: Adjuvant interferon therapy after surgical resection of primary hepatitis C-related hepatocellular carcinoma improves life expectancy through suppression of recurrent cancer with acceptable cost-effectiveness.