If the biopsy shows that cancer is present, your doctor needs to know the stage (extent) of your disease to plan the best treatment. The stage is based on the size of the tumor, whether the cancer has spread and, if so, to what parts of the body.

Staging may require lab tests. It also may involve endoscopy. The doctor uses a thin, lighted tube (endoscope) to check your throat, windpipe, and lungs. The doctor inserts the endoscope through your nose or mouth. Local anesthesia is used to ease your discomfort and prevent you from gagging. Some people also may have a mild sedative. Sometimes the doctor uses general anesthesia to put a person to sleep. This exam may be done in a doctor's office, an outpatient clinic, or a hospital.

The doctor may order one or more imaging tests to learn whether the cancer has spread:

• Dental x-rays: An x-ray of your entire mouth can show whether cancer has spread to the jaw.
• Chest x-rays: Images of your chest and lungs can show whether cancer has spread to these areas.
• CT scan: An x-ray machine linked to a computer takes a series of detailed pictures of your body. You may receive an injection of dye. Tumors in the mouth, throat, neck, or elsewhere in the body show up on the CT scan.
• MRI: A powerful magnet linked to a computer is used to make detailed pictures of your body. The doctor can view these pictures on a monitor and can print them on film. An MRI can show whether oral cancer has spread.

Glossary Terms

A series of detailed pictures of areas inside the body taken from different angles. The pictures are created by a computer linked to an x-ray machine. Also called CAT scan, computed tomography scan, computerized axial tomography scan, and computerized tomography.

A thin, tube-like instrument used to look at tissues inside the body. An endoscope has a light and a lens for viewing and may have a tool to remove tissue.

A procedure that uses an endoscope to examine the inside of the body. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease.

In medicine, a process that makes pictures of areas inside the body. Imaging uses methods such as x-rays (high-energy radiation), ultrasound (high-energy sound waves), and radio waves.

A procedure in which radio waves and a powerful magnet linked to a computer is used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. MRI makes better images of organs and soft tissue than other scanning techniques, such as computed tomography (CT) or x-ray. MRI is especially useful for imaging the brain, the spine, the soft tissue of joints, and the inside of bones. Also called magnetic resonance imaging, NMRI, and nuclear magnetic resonance imaging.

The extent of a cancer in the body. Staging is usually based on the size of the tumor, whether lymph nodes contain cancer, and whether the cancer has spread from the original site to other parts of the body.

A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer.