What is the hepatitis C virus? Does it cause cancer?

Related cancers:


Liver cancer and possibly non-Hodgkin lymphoma and multiple myeloma

Definition:
The hepatitis C virus (HCV), a flavivirus, is causally related to hepatitis C, a type of liver inflammation that is mainly spread via contact with infected blood. A causal relationship has been demonstrated between HCV and liver cancer, which is usually preceded by chronic hepatitis and cirrhosis. Being a ribonucleic acid (RNA) virus, the hepatitis C virus easily mutates, making vaccine development difficult.

Exposure routes: HCV is transmitted by blood-to-blood contact with an infected individual or via blood transfusion with infected blood; rarely, maternal transmission may occur.

Where found: From 150 million to 200 million people worldwide are infected with HCV.

At risk: People who have a history of injected or inhaled drug use, have been exposed to blood via sexual contact, have received a transfusion of unscreened blood, or have been exposed to contaminated instruments during tattooing, ear and body piercing, and dental procedures are at risk. Health care workers are at risk from needlestick injuries. Coinfection with hepatitis B virus (HBV) or the human immunodeficiency virus (HIV) and alcohol abuse put people at risk for chronic hepatitis C, cirrhosis (scarring of the liver), and primary liver cancer, as does having a relative with liver cancer.

Etiology and symptoms of associated cancers:
The hepatitis C virus is the causative agent in primary liver cancer. Moreover, liver cancer does not occur unless cirrhosis is present; 75 percent of those infected with the hepatitis C virus may become chronically infected, with 10 to 20 percent developing cirrhosis over a period of twenty to thirty years, and 1 to 5 percent of them will develop liver cancer.

Specific symptoms of liver cancer are usually absent until cirrhosis has occurred. Signs and symptoms of adult primary liver cancer may include a hard lump below the right side of the rib cage; right side upper abdomen discomfort; right shoulder pain, nausea, and unusual fatigue. Signs and symptoms for multiple myeloma may include bone pain and skeletal and spinal fractures; for Burkitt lymphoma, symptoms may include swollen lymph nodes, abdominal pain, tumors, weight loss, and fatigue.

History: Blood tests were first developed to identify the causative viruses of hepatitis B (1963) and hepatitis A (1973), but some post-transfusion blood samples proved negative for both. In the 1980’s scientists identified another virus as the causative agent of “non-A, non-B hepatitis” and called it hepatitis C virus. In 1990 blood banks began screening donors for the hepatitis C virus, substantially lowering the risk of contracting post-transfusion hepatitis C.