Backgrounder - Oral Cancer


April 5, 2011
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Most oral cancers are located on the sides of the tongue, floor of the mouth and lips. Oral cancer starts in the cells of the mouth. Normally these cells are quite resistant to damage, but repeated injury from smoking, alcohol or even friction may cause sores or painful areas where cancer can start.

What is oral cancer?

Oral cancer refers to all cancers of the oral cavity, which includes the following:

  • lips;
  • tongue;
  • teeth;
  • gums (gingiva);
  • lining inside the lips and cheeks (labial mucosa and buccal mucosa);
  • floor of the mouth;
  • roof of the mouth (palate); and
  • the area behind the wisdom teeth.

Risk Factors

  • Smoking and chewing tobacco, particularly if combined with heavy alcohol consumption.
  • Heavy alcohol consumption, particularly if combined with smoking.
  • Excessive sun exposure, particularly to the lips.
  • Age. People over the age of 40 have a higher risk of developing oral cancer.
  • Gender. Men are more susceptible than women to developing oral cancer. In the past, men had a six-to-one ratio of incidence of oral cancer than women. However, this ratio is narrowing and is now closer to a two-to-one ratio.
  • HPV. More research is emerging that connects Human Papillomavaius infection, especially HPV-16, with oral cancers.
  • A diet low in fruits and vegetables. Fruit and vegetables have a protective factor that is believed to reduce the risk for oral cancers.


See your dentist or another health-care professional if you experience the following symptoms.

  • A sore on the lip or in the mouth that does not heal.
  • A lump on the lip or in the mouth or throat.
  • A white or red patch on the gums, tongue or lining of the mouth.
  • Unusual bleeding, pain or numbness in the mouth.
  • A sore throat that does not go away, or a feeling that something is caught in the throat.
  • Difficulty or pain with chewing or swallowing.
  • Swelling of the jaw that causes dentures to fit poorly or become uncomfortable.
  • A change in the voice and/or pain in the ear.     


  • See a dentist for a dental exam.
  • Quitting (or reducing) your tobacco use lowers your risk of developing oral cancer.
  • Quitting (or reducing) your alcohol use lowers your risk of developing oral cancer.
  • When you are outside and exposed to the sun, use lip balm with UV protection and wear a hat.
  • Eat a healthy diet rich in fruits and vegetables.
  • Brush and floss your teeth daily.


With additional information from Health Canada’s Healthy Living: Oral Health.