Definite risks for mouth and oropharyngeal cancer

Cancers of the mouth and oropharynx are relatively rare. Including cancers of the lip, tongue, mouth and oropharynx, there are about 6,200 people diagnosed in the UK each year. Overall, about 2 out of every 100 cancers diagnosed (2%) are mouth or oropharynx cancers.

As with most cancers, mouth and oropharyngeal cancers are more common in older people. There are very few cases in people under 50. They are twice as common in men than in women. But rates of these cancers in women have been increasing in recent years. This is because women took up smoking in large numbers much later than men and we are now seeing the delayed effects of that.

Smoking tobacco (cigarettes, cigars and pipes) and drinking a lot of alcohol are the main risk factors for mouth and oropharyngeal cancers in the western world. If you smoke you are at a higher than average risk of developing these types of cancers.  And drinking too much alcohol also puts you at risk. A large Cancer Research UK study looking at lifestyle factors that cause cancer found that about a third of cancers of the mouth and throat (30%) were caused by drinking alcohol.Current guidelines in the UK suggest no more than 21 units per week for men, and 14 units per week for women.

Cigarettes and alcohol contain nitrosamines and other chemicals that are known to cause cancer. The nitrosamines in alcohol pass over the mouth, throat and top of the larynx (the epiglottis) as you swallow. When you smoke, the smoke passes through your mouth, throat and the larynx on its way to your lungs. Your risk increases the longer you smoke. 

Remember - If you smoke, you are much more likely to develop these cancers.  If you smoke and regularly drink more than recommended amounts your risk is especially high. Cancers of the mouth or oropharynx do sometimes occur in people who have never smoked or drunk much, but this is rare.

There is more about cancer risk and smoking and about cancer risk and alcohol on our News and Resources website.

Chewing tobacco or betel quid is known to cause mouth cancer and oropharyngeal cancer. It is very common in parts of Asia. It is also popular in some immigrant groups in Europe, North America and Australia.

The term ‘quid’ means a substance or mixture of substances put in the mouth and chewed, usually for long periods. It usually contains tobacco, either on its own or mixed with areca nut (from the Areca catechu tree) and slaked lime. You wrap the mixture in a leaf called a betel leaf, which is where the name betel quid (also called paan) comes from. The harmful substances in tobacco and betel quid can cause cancer if they are in contact with your gums and tongue over long periods. Chewing betel quid without tobacco doubles the risk of mouth cancer, while chewing mixtures containing tobacco increases the risk by 5 times.

People chew tobacco and betel quid for many reasons. It can make you feel good, prevent hunger and sweeten your breath. But more important is that it is a cultural and social habit in many parts of Asia. Mouth cancer is much more common in parts of the world where people chew betel quid. Of the estimated 405,000 cases of oral cancer worldwide each year, two thirds occur in developing countries. In some parts of India, it is the most common type of cancer.

A poor diet may increase your risk of certain types of mouth and oropharyngeal cancer. This may be due to a lack of zinc, or other vitamins and minerals. If you eat a well balanced diet, with plenty of protein, you are unlikely to be short of zinc.

A diet high in fresh fruit and vegetables seems to reduce the risk of developing cancer of the mouth. This may be because these foods contain a lot of antioxidant vitamins and other substances that help prevent damage to body cells.

Vitamin A deficiency increases your risk of developing cancer of the mouth and oropharynx. Poor eating patterns are common in people who drink a lot of alcohol. Poor diet in people who drink heavily may help to explain why alcohol increases the risk of some cancers.

Viruses can help cause some cancers. But this does not mean that you can catch these cancers like an infection. The virus can cause genetic changes in cells that make them more likely to become cancerous in the future.

 Mouth and oropharyngeal cancers have been linked to the human papilloma virus (HPV). There are more than 100 different types of (HPV). Some types are called the wart virus, because they cause warts on the genital area or skin. Other types of HPV are known to increase the risk of some types of cancers. These include cancer of the cervix, vaginal cancer and vulval cancer.

Researchers have found that there is link between HPV type 16 and squamous cell cancer of the oropharynx especially cancer of the tonsil. HPV 16 is also the most common strain found in cervical and genital cancers. HPV infection is common and many people without oral cancer have HPV. Scientists are still trying to find out how people get HPV in the mouth. There is some evidence showing that people may get it through sexual contact through oral sex but people may get it through mouth to mouth contact or in others ways. We need more research to find out. We also need more research to find out if the vaccine could prevent HPV in the mouth. 

Research has found that people have an increased risk of mouth cancer if they have a reduced immunity due to HIV or AIDS. Taking medicines to suppress immunity after organ transplants also gives a higher risk of mouth cancer than in the general population.

Skin cancers are relatively common on the face and neck, as these areas are often exposed to ultraviolet light (UV). Both the sun and tanning beds give off UV rays. These rays can cause skin cancers in unprotected skin. Some studies have shown an increase of skin cancer in people who regularly use sunbeds. Melanoma is the most serious type of skin cancer and can occur on the lip. More than 30 out of every 100 people (30%) diagnosed with cancer of the lip work outdoors and have been exposed to the sun for long periods.

People who have had mouth cancer have an increased risk of getting a second one. Women have a higher risk of a second oral cancer than men.

People who have had some other types of cancer also have an increased risk of oral cancer - these include

• Squamous cell skin cancer
• Cervical, anal or genital cancer in women
• Rectal cancer in men