BOSTON – Direct-acting antiviral therapy does not appear to increase the risk of de novo hepatocellular carcinoma in cirrhotic patients with hepatitis C virus (HCV) infection, according to findings from a prospective cohort study of more than 2,000 patients.
But curing HCV also did not protect patients from hepatocellular carcinoma (HCC), at least during the first 6-12 months after starting treatment, Antonietta Romano, MD, said at the annual meeting of the American Association for the Study of Liver Diseases. Clinicians should continue monitoring HCV patients with advanced liver disease, even after they have achieved sustained viral response, she said.
Recent studies had raised concerns about whether direct-acting antivirals (DAA) increase the risk of HCC, said Dr. Romano of the University of Padova (Italy). To clarify the issue, she and her coinvestigators followed 2,279 HCV patients who received approved DAA regimens. Over a median follow-up time of 305 days, 41 patients developed de novo hepatocellular carcinoma, for an incidence of 1.64 cases per 100 patient-years, Dr. Romano said.
“These results indicate that in cirrhotic patients, the incidence of HCC during the first 6-9 months after initiation of direct-acting antiviral therapy is not different from what we expect in untreated patients, according to historical controls,” she added.
Fully 86% of patients had cirrhosis, of which 91% were Child-Pugh A and 9% were Child-Pugh B, indicating more advanced liver disease, Dr. Romano said. Noncirrhotic patients had an HCC rate of 0.23 cases per 100 patient years – less than one-eighth that for cirrhotic patients (1.93 cases per 100 patient-years). Child-Pugh B patients developed 2.9 cases of HCC per 100 patient years, versus 1.6 for Child-Pugh A patients.
These rates resemble those in historical controls, suggesting that stage of liver disease is the crucial predictor of HCC risk – not DAA therapy, Dr. Romano said. Multivariable analyses supported that conclusion, linking HCC to elevated liver enzymes and to thrombocytopenia but not to DAA regimen, gender, age, or HCV genotype, she reported.
Most HCC cases were diagnosed at least 12 weeks after starting therapy, according to Dr. Romano. Half of patients had a single nodular tumor with a typical vascular pattern, but the other half had a more aggressive multifocal infiltrative pattern. The reason for the high proportion of atypical aggressive pattern was unclear, Dr. Romano said. However, DAA therapy causes HCV to abruptly stop replicating in the liver, leading to marked molecular and immunologic changes that might initially cause microscopic tumors to grow faster than before. So while DAA therapy does not increase the overall risk of HCC, it clearly is not protective, she said.
Nearly 70% of patients in this study were male. About 60% had HCV-1 infection, 22% had HCV-2, 19% had HCV-3, and 8% had HCV-4, Dr. Romano said. In all, 28 of 41 patients who developed HCC had achieved sustained virologic response at 12 weeks, while the other 13 had relapsed.
The investigators received no outside funding for this study. Dr. Romano reported ties to Gilead, Abbvie, and Bristol Myers Squibb.