Impact of hepatitis C elimination on liver cancer incidence in people who inject drugs in Taiwan

Background

People who inject drugs (PWID) are a key population with a high burden of hepatitis C virus (HCV) infection and an elevated risk of hepatocellular carcinoma (HCC). Taiwan launched a nationwide HCV elimination program in 2018, but its impact on high-risk populations remains unclear. This study evaluated trends in HCC incidence among PWID before and after implementation.

Methods

We conducted a retrospective cohort study using Taiwan’s National Health Insurance database. PWID were defined as individuals with a history of injecting drug use, regardless of current use status. PWID with a history of incarceration and chronic HCV infection were included and followed for HCC occurrence from 2008 to 2022. Chronic HCV infection was defined as at least two HCV diagnoses more than 30 days apart or one diagnosis with an HCV RNA test record. HCC incidence rates were calculated across three periods (2008–2012, 2013–2017, and 2018–2022). Incidence was further stratified by HCV treatment status: interferon-based therapy, direct-acting antiviral (DAA) therapy, or no treatment.

Results

A total of 28,782 individuals were included, contributing 181,602.93 person-years. HCC incidence increased from 1.28 per 1,000 person-years in 2008–2012 to 2.15 in 2013–2017, and to 2.91 in 2018–2022. The relative increase was 67.73% before 2018 and 35.32% after 2018 following program implementation. Overall, 19,342 individuals (67%) received HCV treatment, with 78.9% treated after 2018. HCC incidence was lower among treated individuals (interferon: 1.91; DAA: 1.92 per 1,000 person-years) compared with untreated individuals (3.79 per 1,000 person-years).

Conclusions

HCC incidence among PWID continued to rise over time; however, the increasing trend attenuated after program implementation in Taiwan. Lower incidence among treated is consistent with a potential benefit of antiviral therapy. These findings highlight the importance of expanding treatment access for this high-risk populations.

Key messages

• HCC incidence remains high among people who inject drugs despite overall improvements, indicating persistent inequalities in hepatitis C outcomes.

• Lower HCC incidence among treated individuals highlights the importance of expanding access to hepatitis C treatment in high-risk populations.