The estimated risk of hepatocellular carcinoma
is 15 to 20 times as high among persons infected
with HCV as it is among those who are not infected,
with most of the excess risk limited to
those with advanced hepatic fibrosis or cirrhosis.9
HCV infection occurred in large numbers of young
adults in Japan in the 1920s, in southern Europe
in the 1940s, and in North America in the 1960s
and 1970s (with the cases in North America resulting
from the sharing of contaminated needles
by users of injection drugs and from blood transfusions).10
Markers of HCV infection are found in
80 to 90% of patients with hepatocellular carcinoma
in Japan, 44 to 66% in Italy, and 30 to 50%
in the United States.5 It has been projected that
cases of HCV-related hepatocellular carcinoma will
continue to increase in the United States over the
next two to three decades. Risk factors for hepatocellular
carcinoma among persons infected with
HCV include an older age at the time of infection,
male sex, coinfection with the human immunodeficiency
virus or HBV, and probably diabetes or
obesity.11-13 Prolonged, heavy use of alcohol (defined
as daily ingestion of 40 to 60 g of alcohol,
with a standard drink containing 13.7 g, or 0.6 oz)
is a well-established risk factor for hepatocellular
carcinoma both independently (with the risk increased
by a factor of 1.5 to 2.0) and in combination
with HCV infection and, to a lesser extent,
with HBV infection.9