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.

Glossary Terms

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

The inner lining of the cheeks.

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is 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.

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

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

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

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.

An area of abnormal tissue. A lesion may be benign (noncancerous) or malignant (cancerous).

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

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 lip or mouth. This includes the front two thirds of the tongue, the upper and lower gums, the lining inside the cheeks and lips, the bottom of the mouth under the tongue, the bony top of the mouth, and the small area behind the wisdom teeth.

The mouth.

The part of the throat at the back of the mouth. It includes the soft palate, the base of the tongue, and the tonsils.

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 the throat.

The small area behind the wisdom teeth.

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 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 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.