IDDF2024-ABS-0330 Effects of tenofovir alafenamide on the risk of hepatocellular carcinoma: a retrospective cohort study in Hong Kong

<h3>Background</h3> Tenofovir alafenamide (TAF) is a prodrug of tenofovir. We aimed to evaluate the one-year and two-year cumulative incidence of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB) receiving TAF treatment. <h3>Methods</h3> This is a retrospective cohort study in Hong Kong. CHB patients initially treated with TAF for at least six months were included. The baseline was defined as the start date of TAF treatment. Kaplan-Meier’s method was used to evaluate the cumulative incidence of HCC with a 95% confidence interval (CI). <h3>Results</h3> We analyzed 444 CHB patients who initially received TAF for more than six months with a mean age of 54 years old, among whom 262 (59.0%) patients were males. The median TAF treatment duration was 24 months. During a median follow-up duration of 28 months, 10 TAF-treated patients developed HCC. We then censored the time at two years to evaluate the one-year and two-year cumulative HCC incidence. The one-year and two-year cumulative incidences of HCC in TAF-treated patients were 1.2% (95%CI: 0.5% - 3.0%) and 2.9% (95%CI: 1.4% - 5.7%), respectively (IDDF2024-ABS-0330 Figure 1. Cumulative incidence of HCC in TAF-treated CHB patients). The one-year HCC incidence was comparable with that of entecavir (ETV)-treated CHB patients (1.3%, 95%CI: 1.1% - 1.4%) and higher than tenofovir disoproxil fumarate (TDF)-treated CHB patients (0.1%, 95%CI: 0.01% - 0.4%), which were reported by another retrospective cohort study in Hong Kong. <h3>Conclusions</h3> Through 24 months of follow-up, TAF treatment is associated with a comparable HCC risk with ETV treatment but higher than TDF treatment.