Direct-Acting Antivirals Slash the Risk of HCV-Associated Liver Cancer

New direct-acting antivirals (DAA) have revolutionized the treatment of hepatitis C virus (HCV). Results from a study suggest that curing HCV with DAAs reduces the risk of liver cancer by 71%, according to a session at The Liver Meeting.

The CDC estimates that more than 2.7 million Americans have HCV, with a significant population unaware of the infection. Nearly 78% of liver cancers around the world are the result of HCV and hepatitis B virus, according to the study authors.

“The majority of primary liver cancers in the United States occur in patients with hepatitis C virus infection. It is tempting to assume that if we eradicate hepatitis C, the risk of liver cancer will also be eradicated or at least substantially reduced,” said lead investigator George N. Ioannou, MD, MS.

In the new study, the authors examined whether curing HCV reduces the risk of liver cancer associated with the infection and compared patient responses to DAAs and interferon-based treatments.

The authors repeated and extended their research in order to identify additional cases of cancer, especially among patients treated with DAAs, according to the study.

“Patients with hepatitis C may already have developed cirrhosis or advanced fibrosis before the hepatitis C is eradicated, which may put them at risk of liver cancer even after hepatitis C is eradicated,” Dr Ioannou said. “Furthermore, recent studies suggested an increased risk of liver cancer in patients with HCV who were treated with the new DAAs. This made it all the more imperative for us to determine whether DAA‐induced eradication of HCV is associated with a reduction in liver cancer risk using an adequately powered study.”

Included in the study were 62,051 patients administered 83,695 antiviral treatments for HCV between 1999 and 2015. There were 35,873 interferon monotherapies, 26,178 DAA and interferon treatments, and 21,644 DAA monotherapies.

The authors adjusted for potentially confounding factors and discovered 3271 cases of liver cancer diagnosed at least 180 days after antiviral therapy.

Liver cancer risk was highest among patients with cirrhosis and treatment failure at 3.25 per 100 patient-years, followed by patients with cirrhosis and sustained virological response (SVR) at 1.97 cases per 100 patient-years, according to the study.

Patients with no cirrhosis and treatment failure and those with no cirrhosis and SVR had the lowest risk at 0.87 and 0.24 cases per 100 patient-years, respectively.

The authors reported that SVR was linked to a significant reduction in liver cancer risk, regardless of the treatment.

Additionally, treatment with DAA monotherapy or a combination treatment was not linked to an increased risk of cancer compared with interferon monotherapy, according to the study.

Overall, the study found that SVR from DAAs was linked to a 71% reduction in liver cancer risk and is not associated with a higher risk compared with interferon, the authors said.

“Eradicating hepatitis C will have a tremendous benefit in reducing liver cancer in individual patients and in the entire population,” Dr Ioannou concluded. “Physicians and patients should not be withholding antiviral treatment for fear of inducing liver cancer. On the contrary, physicians should be treating hepatitis C specifically to reduce the risk of liver cancer.”