One of the world’s most common viruses appears to significantly raise the risk of cancer, according to a new study from the World Health Organization’s (WHO) cancer research agency.
Most people around the world have been infected with Epstein-Barr virus (EBV) at some point in their lives. It spreads easily through saliva and other bodily fluids and does not usually cause symptoms, but it can lead to mononucleosis, also known as “mono” or “the kissing disease”.
Scientists already knew that EBV, which stays in the body forever, can cause certain cancers, such as lymphomas and a rare form of throat cancer. But until now, there has been little data on the broader health risks.
The new study, which was published in the journal Nature Communications, found that the virus puts people at higher risk for additional cancers, years before they are diagnosed.
Researchers tracked nearly 74,000 people in southern China for eight to 10 years, identifying 1,990 cancer cases. They also tested whether people had EBV antibodies, which are proteins that fight off infections and are stored in the body, serving as a sign that someone has had the virus.
People with EBV antibodies were about five times as likely to develop cancer compared with people who did not have them, according to the study from the WHO’s International Agency for Research on Cancer (IARC) and research centres in China.
The higher the level of antibodies, the higher the cancer risk.
The findings will help scientists “understand the link between [EBV infection] and the risk of various cancer types,” said Dr Zisis Kozlakidis, one of the study’s co-authors and head of IARC’s laboratory support, biobanking, and services unit.
The risks were highest for nasopharyngeal cancer, which is a rare cancer that affects the part of the throat that connects the back of the nose to the back of the mouth. People who had EBV were 26 times as likely to develop this form of cancer than those who were not infected.
Meanwhile, EBV antibodies were also tied to an elevated risk of developing lung cancer, liver cancer, and lymphomas, which are a group of blood cancers.
The study had some limitations. The results may not translate directly to different demographic groups, for example, and other risk factors, such as smoking rates, could have affected the findings.
Even so, researchers said the findings shed new light on cancer-causing viruses such as EBV. They called for more investigation into how exactly the virus causes cancer.
Most people who have had mono will not develop cancer because of EBV, but the virus can cause genetic changes in cells that make them more likely to become cancerous.
Health experts say that if people know their risks, they can watch out for signs of cancers that may be linked to the virus.
