Time association between hepatitis C therapy and hepatocellular carcinoma emergence in cirrhosis: Relevance of non-characterized nodules

© 2019 Background & Aims: Despite direct-acting antivirals being highly effective at eradicating hepatitis C virus infection, their impact on the development of hepatocellular carcinoma (HCC) remains controversial. We analyzed the clinical and radiological outcome of cirrhotic patients treated with interferon-free regimens to estimate the risk of developing HCC. Methods: This was a retrospective multicenter study focusing on cirrhotic patients treated with direct-acting antivirals until December 2016. Clinical and radiologic characteristics were collected before the start of antiviral therapy, at follow-up and at HCC development. Diagnosis of HCC was centrally validated and its incidence was expressed as HCC/100 person-years. Results: A total of 1,123 patients were included (60.6% males, 83.8% Child-Pugh A) and 95.2% achieved a sustained virologic response. Median time of follow-up was 19.6 months. Seventy-two patients developed HCC within a median of 10.3 months after starting antiviral treatment. HCC incidence was 3.73 HCC/100 person-years (95% CI 2.96–4.70). Baseline liver function, alcohol intake and hepatic decompensation were associated with a higher risk of HCC. The relative risk was significantly increased in patients with non-characterized nodules at baseline 2.83 (95% CI 1.55–5.16) vs. absence of non-characterized nodules. When excluding these patients, the risk remained increased. Conclusion: These data expose a clear-cut time association between interferon-free treatment and HCC. The mechanisms involved in the increased risk of HCC emergence in the short term require further investigation. Lay summary: In this cohort of cirrhotic patients, interferon-free therapies achieved a high rate of sustained virologic response (>95%); however, we reported a risk of de novo hepatocellular carcinoma of 3.73 per 100 person-years and a clear-cut time association with antiviral therapy. The time association between starting direct-acting antivirals and developing hepatocellular carcinoma, together with the association with the presence of non-characterized nodules at baseline ultrasound, suggests that antiviral therapy elicits a mechanism (probably immune-related) that primes the growth and clinical recognition of hepatocellular carcinoma early during follow-up. As a result, short-term liver cancer risk is significantly increased.