Cancer is a group of diseases. It occurs when cells become abnormal and divide without control or older. More than 100 different types of cancer are known.
Like all organs of the body, the mouth and throat are made up of many kinds of cells. Cells normally divide in an orderly way to produce more cells only when the body needs them. This process helps keep the body healthy.
Cells that divide when new cells are not needed form to much tissue. The mass of extra tissue, called a tumor, can be benign or malignant.
- Benign tumors are not cancer. They can usually be removed, and in most cases, they don’t grow back. Most important, the cells in benign tumors do not invade other tissues and do not spread to other parts of the body. Benign tumors usually are not a threat to life.
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Malignant tumors are cancer. They can invade and damage nearby tissue and organs. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or the lymphatic system. This is how cancer spreads and forms secondary tumors in other parts of the body. The spread of cancer is called metastasis.
When oral cancer spreads, it usually travels through the lymphatic system. Cancer cells that enter the lymphatic system are carried along by lymph, and almost colorless, watery fluid containing cells that help the body fight infection and disease. Along the lymphatic channels are groups of small, bean-shaped organs called lymph nodes (sometimes called lymph glands). Oral cancer that spread usually travels to the lymph nodes in the neck. It can also spread to other parts of the body. Cancer that spreads is the same disease and has the same name as the original (primary) cancer.