Is exposure to Agent Orange a risk factor for hepatocellular cancer?—A single-center retrospective study in the U.S. veteran population

Approximately 80% to 90% of hepatocellular cancer (HCC) is associated with cirrhosis related to viral hepatitis (1). Hepatitis C virus (HCV) is prevalent in 2% of the world’s population, varying by region, and approximately 15% to 35% of those with HCV related cirrhosis will develop HCC (2). The incidence of HCC is 2% to 6% per year in patients with cirrhosis and HCV (3). With the burden of cirrhosis related to HCV increasing across the globe, and consequently, increasing the incidence of HCC, the identification of risk factors for HCC has become essential. The Veterans Health Administration (VHA) is the single largest HCV care provider in the U.S., with a seroprevalence rate of 5.4% and over 170,000 veterans with confirmed chronic hepatitis C (CHC) (4). The majority of these veterans were born between 1945 and 1965 and likely infected between 1970 and 1999 (4,5). However, about 20% of patients with HCV in Veterans Administration care are undiagnosed (4). Over the past 10 years, the number of HCV infected veterans with cirrhosis has tripled to over 25,000, while over the same time period the cumulative number of HCV-infected veterans diagnosed with HCC has increased ten-fold (6)