OBJECTIVES: Hepatitis C virus (HCV) infection is associated with increased risks of hepatocellular carcinoma (HCC) and non-hepatic cancers. However, it is unclear whether the new direct-acting antivirals (DAAs) for HCV reduce the incidence of these malignancies. This study aims to examine the impact of DAA treatment on the incidence of HCC and non-hepatic cancers among HCV patients in the U.S.

METHODS: A retrospective cohort analysis of the Truven Health MarketScan Database (January 2008- August 2015) was conducted. We included adult patients with newly diagnosed HCV and without a history of cancer. We followed patients from the first HCV diagnosis to the end of enrollment or the occurrence of outcomes, including HCC and non-hepatic cancers. To assess the association between DAA treatment and the risk of developing cancers, a time-varying exposure analysis was performed. We employed cox proportional hazards models to estimate the hazard ratios (HRs) with 95% confidence intervals (CIs). Baseline demographics and comorbidities such as cirrhosis, HBV, HIV, and drug abuse were adjusted in all models.

RESULTS: We identified a total of 46,361 HCV-infected patients (mean age= 52yrs, 61% male), among which 4,311 patients (9.3%) initiated DAA therapy whereas 42,050 (90.7%) patients did not receive any HCV treatment. DAA-treated patients had a higher crude incidence of HCC compared with untreated patients (1,380 vs. 977 per 100,000 person-years), but a lower incidence of non-hepatic cancers (745 vs. 1,216 per 100,000 person-years). After baseline adjustment, patients who received DAA therapy had a 21% decreased the risk of developing HCC (HR=0.79, 95% CI=0.55-1.09) compared to untreated patients, although this was not statistically significant. DAA therapy significantly decreased the risk of developing non-hepatic cancers by 63% (HR=0.37, 95% CI=0.23-0.57).

CONCLUSIONS: DAA treatment is associated with a decreased incidence of non-hepatic cancers among HCV patients, although the association with HCC is not statistically significant.