<P> Many cancers found in the liver are not true liver cancers, but are cancers from other sites in the body that have spread to the liver (known as metastases). Frequently, the site of origin is the gastrointestinal tract, since the liver is close to many of these metabolically active, blood - rich organs near to blood vessels and lymph nodes (such as pancreatic cancer, stomach cancer, colon cancer and carcinoid tumors mainly of the appendix), but also from breast cancer, ovarian cancer, lung cancer, renal cancer, prostate cancer . </P> <P> Because liver cancer is an umbrella term for many types of cancer, the signs and symptoms depend on what type of cancer is present . Cholangiocarcinoma is associated with sweating, jaundice, abdominal pain, weight loss and liver enlargement . Hepatocellular carcinoma is associated with abdominal mass, abdominal pain, emesis, anemia, back pain, jaundice, itching, weight loss and fever . </P> <P> Viral infection with either hepatitis C virus (HCV) or Hepatitis B virus (HBV) is the chief cause of liver cancer in the world today, accounting for 80% of hepatocellular carcinoma (HCC). The viruses cause HCC because massive inflammation, fibrosis and eventual cirrhosis occurs within the liver . HCC usually arises after cirrhosis, with an annual incidence of 1.7% in cirrhotic HCV - infected individuals . Around 5 - 10% of individuals that become infected with HBV become chronic carriers, and around 30% of these acquire chronic liver disease, which can lead to HCC . HBV infection is also linked to cholangiocarcinoma . The role of viruses other than HCV or HBV in liver cancer is much less clear, although there is some evidence that co-infection of HBV and hepatitis D virus may increase the risk of HCC . </P> <P> Many genetic and epigenetic changes are formed in liver cells during HCV and HBV infection, which is a major factor in the production of the liver tumors . The viruses induce malignant changes in cells by altering gene methylation, affecting gene expression and promoting or repressing cellular signal transduction pathways . By doing this the viruses can prevent cells from undergoing a programmed form of cell death (apoptosis) and promote viral replication and persistence . </P>

Which type of hepatitis is responsible for 50 to 76 of all patients with liver cancer