What is prevention?
General Information About Oral Cancer
Oral Cancer Prevention
Get More Information From NCI
Changes to This Summary (12/19/2008)
Questions or Comments About This Summary
About PDQ

What is prevention?

Cancer prevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will lower the number of deaths caused by cancer.

To prevent new cancers from starting, scientists look at risk factors and protective factors. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.

Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Regular exercise and a healthy diet may be protective factors for some types of cancer. Avoiding risk factors and increasing protective factors may lower your risk but it does not mean that you will not get cancer.

Different ways to prevent cancer are being studied, including:

• Changing lifestyle or eating habits.
• Avoiding things known to cause cancer.
• Taking medicines to treat a precancerous condition or to keep cancer from starting.

See the following PDQ summaries for information about screening, diagnosis, and treatment of oral cancer:

• Oral Cancer Screening ¹
• Lip and Oral Cavity Cancer Treatment ²
• Oropharyngeal Cancer Treatment ³

General Information About Oral Cancer

Key Points for This Section

Oral cancer is a disease in which malignant (cancer) cells form in the lips, mouth, or throat. Oral cancer is more common in men than in women.

Oral cancer is a disease in which malignant (cancer) cells form in the lips, mouth, or throat.

Oral cancer may form in any of three main areas:

• Lips.
• Oral cavity, which includes:
  • The front two thirds of the tongue.
  • The gingiva (gums).
  • The buccal mucosa (the lining of the inside of the cheeks).
  • The floor (bottom) of the mouth under the tongue.
  • The hard palate (the front, bony part of the roof of the mouth).
  • The retromolar trigone (the small area behind the wisdom teeth).
• Oropharynx, which includes:
  • The middle part of the pharynx (throat) behind the mouth.
  • The back one-third of the tongue.
  • The soft palate (the back, soft part of the roof of the mouth).
  • The side and back walls of the throat.
  • The tonsils.

Most oral cancers start in squamous cells (thin, flat cells) that line the lips, oral cavity, and oropharynx. Cancer that forms in squamous cells is called squamous cell carcinoma. Lesions on the mucous membranes (the lining of the mouth and throat), including leukoplakia (an abnormal white patch of cells) and erythroplakia (an abnormal red patch of cells), may develop into squamous cell carcinoma.

Oral cancer is more common in men than in women.

Most patients with oral cancer are men. However, the number of women in the United States diagnosed with tongue cancer has increased greatly over the past 20 years.

In Western countries, such as the United States, the most common areas for oral cancer are the tongue and the floor of the mouth. In parts of the world where chewing tobacco or betel nuts is common, oral cancer often forms in the retromolar trigone and buccal mucosa.

Oral Cancer Prevention

Key Points for This Section

Avoiding risk factors and increasing protective factors may help prevent cancer. The following risk factors may increase the risk of oral cancer: Tobacco use Alcohol use Sun exposure HPV infection Marijuana use The following protective factors may decrease the risk of oral cancer: Dietary factors Chemoprevention Cancer prevention clinical trials are used to study ways to prevent cancer. New ways to prevent oral cancer are being studied in clinical trials.

Avoiding risk factors and increasing protective factors may help prevent cancer.

Avoiding cancer risk factors such as smoking, being overweight, and lack of exercise may help prevent certain cancers. Increasing protective factors such as quitting smoking, eating a healthy diet, and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.

The following risk factors may increase the risk of oral cancer:

Tobacco use

Using tobacco is the leading cause of oral cancer.

All forms of tobacco, including cigarettes, pipes, cigars, and chewing (smokeless) tobacco, are linked to oral cancer. The risk of oral cancer increases with the number of cigarettes smoked per day. Tobacco use is most likely to cause oral cancer in the floor of the mouth, but also causes cancer in the oral cavity and oropharynx and on the lips.

The risk of oral cancer is greater in people who use both tobacco and alcohol than it is in people who use only tobacco or only alcohol.

Tobacco users who have had oral cancer may develop second cancers in the oral cavity or nearby areas, including the nose, throat, vocal cords, esophagus, and trachea (windpipe).

Results from clinical trials have shown that when a person stops smoking cigarettes, the risk of oral cancer decreases by one-half (50%) within 5 years. Within 10 years of quitting, the risk of oral cancer is the same as for a person who never used tobacco.

Alcohol use

Using alcohol is a major risk factor for oral cancer.

The risk of oral cancer increases with the number of alcoholic drinks consumed per day. Alcohol use is also a risk factor for leukoplakia (an abnormal white patch of cells) and erythroplakia (an abnormal red patch of cells). Leukoplakia and erythroplakia lesions on the mucous membranes may become cancer.

The risk of oral cancer is greater in people who use both alcohol and tobacco than it is in people who use only alcohol or only tobacco.

Results from clinical trials have not shown a decrease in the risk of oral cancer when a person stops drinking alcohol.

Sun exposure

Being exposed to sunlight may increase the risk of lip cancer, which occurs most often on the lower lip. Avoiding the sun and/or using lip balm with sunscreen or using colored lipstick may decrease the risk of lip cancer.

HPV infection

Being infected with a certain type of human papillomavirus (HPV) may increase the risk of oral cancer.

Marijuana use

Using marijuana may increase the risk of oral cancer. Marijuana use by a person with high-risk HPV infection may further increase the risk of oral cancer.

The following protective factors may decrease the risk of oral cancer:

Dietary factors

Eating a diet high in fruits and fiber -rich vegetables may lower the risk of developing oral cancer.

Chemoprevention

Chemoprevention is the use of drugs, vitamins, or other agents to prevent or delay the growth of cancer.

Studies of chemoprevention are under way in patients at high risk for oral cancer, including those with precancerous oral lesions and those with a history of oral cancer. Check NCI's Cancer Clinical Trials Registry for chemoprevention trials for cancer of the lip and oral cavity ⁴ and oropharynx ⁵.

Cancer prevention clinical trials are used to study ways to prevent cancer.

Cancer prevention clinical trials are used to study ways to lower the risk of developing certain types of cancer. Some cancer prevention trials are conducted with healthy people who have not had cancer but who have an increased risk for cancer. Other prevention trials are conducted with people who have had cancer and are trying to prevent another cancer of the same type or to lower their chance of developing a new type of cancer. Other trials are done with healthy volunteers who are not known to have any risk factors for cancer.

The purpose of some cancer prevention clinical trials is to find out whether actions people take can prevent cancer. These may include eating fruits and vegetables, exercising, quitting smoking, or taking certain medicines, vitamins, minerals, or food supplements.

New ways to prevent oral cancer are being studied in clinical trials.

Clinical trials are taking place in many parts of the country. Information about clinical trials can be found in the Clinical Trials section of the NCI Web site ⁶. Check NCI's PDQ Cancer Clinical Trials Registry for lip and oral cavity cancer prevention trials ⁷ and oropharyngeal cancer prevention trials ⁸ that are now accepting patients.

Get More Information From NCI

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Changes to This Summary (12/19/2008)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Editorial changes were made to this summary.

Questions or Comments About This Summary

If you have questions or comments about this summary, please send them to Cancer.gov through the Web site’s Contact Form ¹². We can respond only to email messages written in English.

About PDQ

PDQ is a comprehensive cancer database available on NCI's Web site.

PDQ is the National Cancer Institute's (NCI's) comprehensive cancer information database. Most of the information contained in PDQ is available online at NCI's Web site ¹⁰. PDQ is provided as a service of the NCI. The NCI is part of the National Institutes of Health, the federal government's focal point for biomedical research.

PDQ contains cancer information summaries.

The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries are available in two versions. The health professional versions provide detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions provide current and accurate cancer information.

The PDQ cancer information summaries are developed by cancer experts and reviewed regularly.

Editorial Boards made up of experts in oncology and related specialties are responsible for writing and maintaining the cancer information summaries. The summaries are reviewed regularly and changes are made as new information becomes available. The date on each summary ("Date Last Modified") indicates the time of the most recent change.

PDQ also contains information on clinical trials.

A clinical trial is a study to answer a scientific question, such as whether a certain drug or nutrient can prevent cancer. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients and those who are at risk for cancer. During prevention clinical trials, information is collected about the effects of a new prevention method and how well it works. If a clinical trial shows that a new method is better than one currently being used, the new method may become "standard." People who are at high risk for a certain type of cancer may want to think about taking part in a clinical trial.

Listings of clinical trials are included in PDQ and are available online at NCI's Web site ¹³. Descriptions of the trials are available in health professional and patient versions. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237).

Glossary Terms

Not normal. An abnormal lesion or growth may be cancer, premalignant (likely to become cancer), or benign (not cancer).

A chemical substance found in beer, wine, and liquor. Alcohol is also found in some medicines, mouthwashes, essential oils (scented liquid taken from plants), and household products.

The inner lining of the cheeks.

A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

The use of drugs, vitamins, or other agents to try to reduce the risk of, or delay the development or recurrence of, cancer.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.

The process of identifying a disease, such as cancer, from its signs and symptoms.

The things a person eats and drinks.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

An abnormal patch of red tissue that forms on mucous membranes in the mouth and may become cancer. Tobacco (smoking and chewing) and alcohol may increase the risk of erythroplakia.

The muscular tube through which food passes from the throat to the stomach.

In food, fiber is the part of fruits, vegetables, legumes, and whole grains that cannot be digested. The fiber in food may help prevent cancer. In the body, fiber refers to tissue made of long threadlike cells, such as muscle fiber or nerve fiber.

The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.

The tissue of the upper and lower jaws that surrounds the base of the teeth. Also called gums.

The front, bony part of the roof of the mouth.

A type of virus that can cause abnormal tissue growth (for example, warts) and other changes to cells. Infection for a long time with certain types of human papillomavirus may cause cervical cancer. Human papillomavirus may also play a role in some other types of cancer. Also called HPV.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

An area of abnormal tissue. A lesion may be benign (not cancer) or malignant (cancer).

An abnormal patch of white tissue that forms on mucous membranes in the mouth and other areas of the body. It may become cancer. Tobacco (smoking and chewing) and alcohol may increase the risk of leukoplakia in the mouth.

The dried leaves and flowering tops of the Cannabis sativa plant, or an extract from the plant. Marijuana is being studied in the treatment of nausea and vomiting caused by chemotherapy or opiate drugs, such as morphine sulfate. Marijuana is also being studied in the treatment of pain.

Refers to the practices and procedures used for the prevention, treatment, or relief of symptoms of a diseases or abnormal conditions. This term may also refer to a legal drug used for the same purpose.

In medicine, a mineral is a nutrient that is needed in small amounts to keep the body healthy. Mineral nutrients include the elements calcium, magnesium, and iron.

The moist, inner lining of some organs and body cavities (such as the nose, mouth, lungs, and stomach). Glands in the mucous membrane make mucus (a thick, slippery fluid). Also called mucosa.

Cancer that forms in tissues of the oral cavity (the mouth) or the oropharynx (the part of the throat at the back of the mouth).

Refers to the mouth. It includes the lips, the lining inside the cheeks and lips, the front two thirds of the tongue, the upper and lower gums, the floor of the mouth under the tongue, the bony roof of the mouth, and the small area behind the wisdom teeth.

The part of the throat at the back of the mouth behind the oral cavity. It includes the back third of the tongue, the soft palate, the side and back walls of the throat, and the tonsils.

Being too heavy for one’s height. Excess body weight can come from fat, muscle, bone, and/or water retention. Being overweight does not always mean being obese.

PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, complementary and alternative medicine, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information, and more specific information about PDQ, can be found on the NCI's Web site at http://www.cancer.gov/cancertopics/pdq. Also called Physician Data Query.

The hollow tube inside the neck that starts behind the nose and ends at the top of the trachea (windpipe) and esophagus (the tube that goes to the stomach). The pharynx is about 5 inches long, depending on body size. Also called throat.

A term used to describe a condition that may (or is likely to) become cancer. Also called premalignant.

In medicine, action taken to decrease the chance of getting a disease or condition. For example, cancer prevention includes avoiding risk factors (such as smoking, obesity, lack of exercise, and radiation exposure) and increasing protective factors (such as getting regular physical activity, staying at a healthy weight, and having a healthy diet).

Something that may decrease the chance of getting a certain disease. Some examples of protective factors for cancer are getting regular physical activity, staying at a healthy weight, and having a healthy diet.

The small area behind the wisdom teeth.

Something that increases the chance of developing a disease. Some examples of risk factors for cancer are age, a family history of certain cancers, use of tobacco products, being exposed to radiation or certain chemicals, infection with certain viruses or bacteria, and certain genetic changes.

A person who has studied science, especially one who is active in a particular field of investigation.

Checking for disease when there are no symptoms. Since screening may find diseases at an early stage, there may be a better chance of curing the disease. Examples of cancer screening tests are the mammogram (breast), colonoscopy (colon), Pap smear (cervix), and PSA blood level and digital rectal exam (prostate). Screening can also include checking for a person’s risk of developing an inherited disease by doing a genetic test.

The back, muscular (not bony) part of the roof of the mouth.

Flat cell that looks like a fish scale under a microscope. These cells cover inside and outside surfaces of the body. They are found in the tissues that form the surface of the skin, the lining of the hollow organs of the body (such as the bladder, kidney, and uterus), and the passages of the respiratory and digestive tracts.

Cancer that begins in squamous cells, which are thin, flat cells that look like fish scales. Squamous cells are found in the tissue that forms the surface of the skin, the lining of the hollow organs of the body, and the passages of the respiratory and digestive tracts. Also called epidermoid carcinoma.

A substance that helps protect the skin from the sun's harmful rays. Sunscreens reflect, absorb, and scatter both ultraviolet A and B radiation to provide protection against both types of radiation. Using lotions, creams, or gels that contain sunscreens can help protect the skin from premature aging and damage that may lead to skin cancer.

Adding nutrients to the diet.

The hollow tube inside the neck that starts behind the nose and ends at the top of the trachea (windpipe) and esophagus (the tube that goes to the stomach). The throat is about 5 inches long, depending on body size. Also called pharynx.

A plant with leaves that have high levels of the addictive chemical nicotine. The leaves may be smoked (in cigarettes, cigars, and pipes), applied to the gums (as dipping and chewing tobacco), or inhaled (as snuff). Tobacco leaves also contain many cancer-causing chemicals, and tobacco use and exposure to secondhand tobacco smoke have been linked to many types of cancer and other diseases. The scientific name is Nicotiana tabacum.

Cancer that begins in the tongue. When the cancer begins in the front two-thirds of the tongue, it is considered to be a type of oral cavity cancer; when the cancer begins in the back third of the tongue, it is considered to be a type of oropharyngeal or throat cancer.

One of two small masses of lymphoid tissue on either side of the throat.

The airway that leads from the larynx (voice box) to the bronchi (large airways that lead to the lungs). Also called windpipe.

A nutrient that the body needs in small amounts to function and stay healthy. Sources of vitamins are plant and animal food products and dietary supplements. Some vitamins are made in the human body from food products. Vitamins are either fat-soluble (can dissolve in fats and oils) or water-soluble (can dissolve in water). Excess fat-soluble vitamins are stored in the body’s fatty tissue, but excess water-soluble vitamins are removed in the urine. Examples are vitamin A, vitamin C, and vitamin E.

One of two small bands of muscle within the larynx that vibrates to produce the voice.

The last tooth to come in at the back of each side of the upper and lower jaws. These teeth usually come in between 17 and 23 years of age, but not everyone has them. Also called third molar.