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Oral cancer

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What is oral cavity cancer?

Oral cavity cancer is a malignant tumour that starts in cells of the mouth. Malignant means that it can spread, or metastasize, to other parts of the body.

The oral cavity is part of the digestive system. The structures in the oral cavity help you speak, taste and chew. The oral cavity includes the lips, cheeks, gums and teeth. It also includes the part of the tongue in the mouth (called the oral tongue), the bony part of the roof of the mouth (called the hard palate) and the floor of the mouth under the tongue. A mucous membrane lines and protects the inside of the oral cavity.

Cells in the mouth sometimes change and no longer grow or behave normally. These changes may lead to non-cancerous, or benign, conditions. These conditions include candidiasis (also called thrush) and aphthous ulcers\(also called canker sores). Changes to cells in the oral cavity can also lead to non-cancerous tumours such as hyperplasias and papillomas.

Sometimes changes to cells in the oral cavity can cause precancerous conditions. This means that the cells are not yet cancer but there is a higher chance these abnormal changes will become cancer. The most common precancerous conditions of the oral cavity are leukoplakia and erythroplakia.

In some cases, changes to cells in the oral cavity can cause cancer. Most often, oral cavity cancer starts in flat, thin cells called squamous cells. These cells make up the squamous epithelium, which is a layer of the mucous membrane. This type of cancer is called squamous cell carcinoma of the oral cavity.

Other types of cancer can also develop in the oral cavity, but they are rare. These include salivary gland cancer and melanoma.

Diagram of oral cavity

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