Cells divide in an orderly, controlled way to produce more cells when more cells are needed in the body. When cells divide in an abnormal, uncontrolled way, they can form either a benign or malignant tumor. Benign tumors are not cancerous and usually are not a threat to life. They can usually be removed, and generally will not grow back. Benign tumor cells do not invade other tissues and do not spread to other parts of the body.
Malignant tumors are cancerous.
Cancer cells can spread to nearby healthy cells and destroy them. The cancerous cells can also invade other parts of the body. Cancerous cells in the oral cavity and pharynx can spread to nearby lymph nodes and to other parts of the body. The spread of cancer is called metastasis . Over 90 percent of oral cancer cases occur in people who are over age 45.