Oral cancer is a disease in which malignant (cancer) cells form in the lips, oral cavity, or oropharynx.

Oral cancer may develop in any of the following areas:

• Lips.
• Oral cavity:
  • 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 of the roof of the mouth).
  • The retromolar trigone (the small area behind the wisdom teeth).
• Oropharynx:
  • The middle part of the pharynx (throat) behind the mouth.
  • The back one third of the tongue.
  • The soft palate (the back of the roof of the mouth).
  • The side and back walls of the throat.
  • The tonsils.

Most oral cancers start in squamous cells, the thin, flat cells that line the lips, oral cavity, and oropharynx. Cancer that forms in squamous cells is called squamous cell carcinoma.

The number of new cases of oral cancer and the number of deaths from oral cancer have been decreasing slowly.

Most oral cancers occur in people older than 45 years, and more often in blacks than in whites. Even though the total number of new cases and deaths from oral cancer has decreased slowly over the past 20 years, the number of new cases of oral cancer (especially of the tongue) has been increasing in adults younger than 40 years.

Tobacco and alcohol use can affect the risk of developing oral cancer.

Anything that increases the chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Risk factors for oral cancer include the following:

• Using tobacco products (includes cigarettes, cigars, pipes, and smokeless and chewing tobacco).
• Heavy alcohol use.
• Chewing betel nuts.
• Being infected with a certain type of human papillomavirus (HPV).
• Being exposed to sunlight (lip cancer only).
• Being male.