Antiviral Treatment Reduces Risk of Development of Lung Cancer and Non-Hodgkin Lymphoma in Patients with Chronic Hepatitis C.

[BACKGROUND] Antiviral treatment for hepatitis C virus (HCV) has been shown to reduce risk of liver cancer, but there are few studies on its impact on the risk of non-liver cancers. We used a large cohort of patients with HCV with extensive follow-up to investigate whether receipt of antiviral therapy affects the risk of extrahepatic cancers.

[METHODS] A total of 17,485 patients with HCV were followed until incidence of lung cancer, non-Hodgkin lymphoma (NHL), breast or prostate cancer, death, or last follow-up. We used multivariable modeling with time-varying covariates and propensity scores to adjust for treatment selection bias; we also applied generalized estimating equations with a multinominal link function for discrete time-to-event data. Death was considered a competing risk.

[RESULTS] After 15 years of follow-up, we identified 408 incident cases of cancers, namely 140 lung, 72 NHL, 81 breast (female), and 115 prostate cancer cases. Compared with no treatment, patients who receive either direct-acting antivirals or IFN-based treatment had significantly lower risk of lung cancer [HR = 0.35, 95% confidence interval, 0.24-0.52 for achieving sustained virologic response (SVR); HR = 0.34, 95% confidence interval, 0.21-0.55 for treatment failure]. Risk of NHL was reduced only among patients who achieved SVR. There were no significant associations between antiviral therapy and risks of breast and prostate cancers.

[CONCLUSIONS] Antiviral treatment for HCV independently reduced the risk of lung cancer, whereas the protective association with NHL was limited to patients achieving SVRs.

[IMPACT] Our findings support the importance of timely initiation antiviral therapy in patients with chronic HCV.