Metformin lowers HCC risk after antiviral therapy in diabetic patients with hepatitis C

Treatment with metformin results in a significant reduction in hepatocellular carcinoma (HCC) incidence following successful antiviral therapy in individuals with diabetes mellitus and chronic hepatitis C (CHC), a recent study has shown.

This large-scale, multicentre cohort study was conducted in Taiwan and included 7,249 individuals with CHC who achieved a sustained virological response (SVR) following interferon-based therapy. The authors identified HCC cases at least 1 year after SVR through linkage to the catastrophic illness and cancer registry databases.

Of the participants, 781 (10.8 percent) had diabetes and 647 (82.8 percent) were metformin users. Some 277 patients developed new-onset HCC during a median follow-up of 4.4 years.

The cumulative incidence of HCC at 5 years was 10.9 percent in nonusers of metformin (adjusted hazard ratio [aHR], 2.83, 95 percent confidence interval [CI], 1.57‒5.08) and 2.6 percent in metformin users (aHR, 1.46, 95 percent CI, 0.98‒2.19) compared to 3.0 percent in those without diabetes.

Cox regression analysis revealed cirrhosis to be the most significant factor associated with higher HCC risk, followed by diabetes mellitus nonmetformin use, older age, male sex, and obesity. On the other hand, hyperlipidemia with statin use correlated with a reduced HCC risk.

Using cirrhosis and diabetes mellitus nonmetformin use, the two most crucial risk factors, a simple risk model was constructed to predict HCC risk among individuals with CHC after SVR. Notably, use of metformin induced a decrease in the risk of all liver-related complications.

“A simple risk stratification model comprising cirrhosis and DM nonmetformin use could predict long-term outcomes in individuals with CHC after SVR,” the authors said.