A recent retrospective study found that patients with hepatitis C virus (HCV), who had cleared the virus using direct-acting antiviral (DAA) drugs, showed a considerably reduced risk of the most common type of adult liver cancer: hepatocellular carcinoma (HCC).
The Centers for Disease Control and Prevention report
that liver cancer, primarily HCC, is “the third leading cause of death from cancer worldwide,” and is the fastest growing cause of cancer-related deaths in the United States. Chronic hepatitis B (HCV) and HCV infections account for a staggering 78% of HCC cases on a global scale.
In the study
, published last month in Gastroenterology
, a team of researchers from the Veterans Affairs Medical Center and Baylor College of Medicine, both located in Houston, Texas, set out to examine the risks and determinants of HCC in hepatitis C patients who had reached sustained virologic response (SVR) with direct-acting antiviral drugs.
The authors noted that data on HCC risk following DAA-induced SVR are still "sparse and conflicting.” For instance, some studies suggest an unusually high rate of liver cancer after DAA-induced SVR, while other research has found that SVR is associated with decreased HCC incidence in patients with cirrhosis compared with patients who had not cleared the virus.
The authors conducted their retrospective cohort investigation by studying 22,500 HCV patients who were treated with DAAs in Veterans Health Administration hospitals in 2015. Among these individuals, 19,518 had achieved SVR, and 2,982 had not; their mean age was 61.6 years old and 39% had cirrhosis.
Their findings? SVR was associated with a 76% reduction in HCC risk in patients treated with DAAs when compared with patients who did not achieve SVR. In addition, the relative benefit of being cured with antiviral therapy persisted after accounting for demographic and clinical differences. Furthermore, the absolute risk for HCC remained high in HCV patients with cirrhosis; these individuals should be considered for ongoing surveillance, the researchers said.
“These data show that successful eradication of HCV confers a benefit in DAA treated patients,” the researchers wrote.
Despite this benefit, the absolute risk of HCC persisted in patients who achieved SVR. Liver cancer developed in 183 of these individuals for an annual incidence of 0.9%; this was higher than in patients who’d been cured with interferon-based therapies, where the HCC incidence was about 0.3%, according to previous studies. However, there was no evidence to suggest that DAAs promote HCC.
The researchers speculated that DAAs offer a potential cure for all HCV patients, including individuals with advanced cirrhosis and those who use alcohol. These characteristics are independently associated with risk of HCC in hepatitis C patients.
With interferon-based therapies, such individuals were typically not treated or had poor responses, according to the study.
“The treated population has changed significantly in the DAA era to include many patients with other HCC risk factors,” the authors wrote. “These differences likely explain why the newer cohorts of DAA treated patients face higher absolute HCC risk than expected based on historic data.”
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