Nasopharyngeal Cancer Causes, Risk Factors, and Prevention

Epstein-Barr virus (EBV) infection has been linked to the development of NPC, as well as certain lymphomas. It is often found in the non-keratinizing, undifferentiated type of NPC. 

Infection with EBV is very common throughout the world, often happening in children. In the United States, where infection with this virus tends to occur in teens, it's commonly known as mononucleosis or mono.

Most people who get EBV do not develop nasopharyngeal cancer.

Most people recover from EBV infection without problems because their immune system controls the virus. But in some people, the DNA of the virus mixes with the DNA of cells in the nasopharynx.

DNA is the body’s instruction system for how cells grow and divide. When Epstein-Barr virus DNA mixes with human DNA, it can send the wrong signals, causing cells to grow in an unhealthy way. Over time, this abnormal growth can lead to cancer. For more on how changes in the DNA of a gene can lead to cancer, see Genes and Cancer.

Infection with EBV alone isn’t enough to cause nasopharyngeal cancer, because infection with this virus is very common and this cancer is very rare. Other factors, such as a person’s genes or smoking, may affect how the body deals with EBV, which may in turn affect how EBV plays a part in the development of nasopharyngeal cancer.

Human papillomavirus (HPV) is a group of more than 150 types of viruses. Infection with certain types of HPV can cause some forms of cancer, including cancers of the mouth and throat.

Some research shows that certain high-risk types of HPV may be linked to a small group of nasopharyngeal cases, especially in younger people who don’t smoke.

See HPV (human papillomavirus) to learn more about HPV infection and vaccines to prevent it.

Eating a diet high in salt-cured fish and meat seems to increase the ability of Epstein-Barr virus (EBV) to cause nasopharyngeal cancer. Studies show that foods preserved in this way may produce chemicals that can damage DNA. The damaged DNA then changes a cell’s ability to control its growth and reproduction.

In contrast, some studies have suggested that diets high in nuts, legumes, fruits, and vegetables and low in dairy products and meat may help lower the risk of NPC.

People who live in parts of Asia, northern Africa, and the Arctic region where NPC is common typically eat diets very high in salt-cured fish and meat starting at an early age. The process of cooking the salted food seems to create chemicals, such as nitrosamine, which is a probable carcinogen.

The rate of this cancer is dropping in southeast China and Singapore. This might be partly due to people eating less salt-cured fish.

Family members of people with NPC are more likely to get this cancer. It's not known if this is because of inherited genes, shared environmental factors such as the same diet or living quarters, or some combination of these.

Studies have found that people with certain inherited tissue types have an increased risk of developing NPC. Just as people have different blood types, they also have different tissue types. Tissue types affect immune responses, so this may be related to how a person's body reacts to EBV infection.

In areas of the world where nasopharyngeal cancer is not common, older age is a risk factor. In places where NPC is more common, this cancer tends to be seen in younger people.

NPC is most common in Asia, specifically Singapore, Vietnam, the Philippines, and eastern and southern China, including Hong Kong. It is also common in parts of North Africa and the Middle East, as well as the Arctic.

People born in south China have a lower risk of NPC if they move to a part of the world with lower rates of the disease, such as the US or Japan. However, their risk of NPC is still higher than that of people who are native to lower-risk regions. Over time, this risk seems to go down. The risk also goes down in new generations.

Although White people born in the United States have a low risk of NPC, White people born in China have a higher risk.

Many studies have found that smoking may contribute to the development of nasopharyngeal cancer. Smoking might increase the risk of NPC by reactivating an Epstein-Barr virus infection.

Studies have linked heavy drinking of alcohol to the development of NPC. This is seen more often in the US and Europe than in other parts of the world.