Influence of Interferon-free Direct-acting Antiviral Therapy on Primary Hepatocellular Carcinoma Recurrence: A Landmark Time Analysis and Time-dependent Extended Cox Proportional Hazards Model Analysis

OBJECTIVE: The influence of interferon (IFN)-free direct-acting antiviral (DAA) on hepatocellular carcinoma (HCC) recurrence remains unclear. Previous retrospective analyses revealed that the time interval between HCC curative treatment and IFN-free DAA induction is the critical factor affecting HCC recurrence. Thus, this study aimed to examine the influence of DAA therapy on HCC recurrence considering this interval. METHODS: Factors contributing to HCC recurrence were retrospectively analyzed using a landmark time analysis and time-dependent extended Cox proportional hazards model. PATIENTS: After screening 620 patients who were diagnosed with primary HCC from January 2001 to December 2016, 76 patients with early-stage (primary and solitary) disease who received curative treatment and were positive for serum hepatitis C virus RNA were included. RESULTS: HCC recurrence was observed in 8 of 17 (47.1%) patients who had received IFN-free DAA therapy and 45 of 59 (76.3%) who had not. No significant difference was seen between the IFN-free DAA (-) and IFN-free DAA (+) groups in the landmark time and time-dependent Cox proportional hazards model analyses. However, IFN-free DAA therapy tended to decrease the HCC recurrence rate after curative treatment for primary HCC in patients with chronic hepatitis. In addition, IFN-free DAA therapy tended to decrease the second HCC recurrence rate after treatment for the first HCC recurrence. CONCLUSION: Our results, with a consideration of the time interval between HCC curative treatment and IFN-free DAA induction, showed that IFN-free DAA therapy was not associated with early-stage HCC recurrence after curative treatment.