Hepatitis viruses and cancer
About hepatitis viruses
Hepatitis viruses are a group of different viruses that can infect humans. Two types of hepatitis viruses, hepatitis B virus (HBV) and hepatitis C virus (HCV), can cause cancer. These viruses are usually spread through blood-to-blood contact, for example by sharing unsterilised needles, razors or toothbrushes, but they can also be spread through unprotected sex. People may also get infected by having contaminated blood transfusions, but since 1991 all donated blood in the UK is tested to make sure this doesn’t happen.
Most HBV infections can be fought off by the immune system and don’t cause any major harm. But in some cases HBV infections can become persistent and cause long term inflammation in the liver and other problems. And in the case of HCV, over three quarters of infections become persistent.
Globally, infection with HBV and HCV is common. Estimates suggest that around 350 million people live with persistent HBV infection and more than 170 million live with persistent HCV worldwide. But most of these people live in developing countries and rates in the UK are much lower. HCV is the most common type of viral hepatitis in the UK.
What cancers are linked to hepatitis viruses?
In the UK, liver cancer risk is around 20 times higher in people with HBV and/or HCV infection than in uninfected people. The risk is especially raised in those who are older, male, or have been to hospital with an alcohol-related health problem in the past. Up to 9 in 10 patients with HBV- or HCV-linked liver cancer also have cirrhosis, but infection with these viruses can also be linked to liver cancer without cirrhosis.
How can hepatitis viruses cause cancer?
Hepatitis viruses are carried in people’s blood and can cause inflammation in the liver. Exactly how hepatitis viruses can cause cancer is not yet fully understood, but it is likely that this may be different for different types of hepatitis virus. It might be that the viruses cause persistent liver inflammation, or change normal functions inside cells.
Reducing the risk
To avoid infection with hepatitis viruses it is important to avoid sharing needles, razors, toothbrushes or anything else that could come into contact with someone’s blood. It’s also important to avoid having medical or dental treatments or getting tattoos or piercings in unhygienic environments. And it’s best to keep sexual contact safer, by using a barrier method shown to reduce spread, like a condom.
A vaccine to protect people against infection with HBV is available on the NHS. It is free of charge for people at risk, including health workers, men who have sex with men, close family of someone known to have HBV, and people who inject drugs. If you think you are at risk, you can visit your GP or a sexual health clinic to ask if you could get the vaccine. HBV vaccination is also recommended for people travelling to countries where HBV is common. If you are not at risk and want the vaccine, you can visit your GP or a travel clinic and pay to get vaccinated.
There is no vaccine available to protect from HCV at the moment.