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Oral Cancer Diagnosis

Since early diagnosis improves your chances for successful treatment, it’s important for oral (mouth) cancers and pre-cancerous lesions to be found as soon as possible. MD Anderson uses the most advanced techniques and technology to determine if a tumor is benign (not cancer), pre-cancer or cancer. In addition, we are working on new less-invasive optical techniques to help detect oral cancers.

Oral Cancer Diagnostic Tests

If you have symptoms that may indicate cancer, your dentist or doctor will examine the inside of your cheeks and lips, the floor and roof of the mouth, the tongue and the lymph nodes in your neck. He or she will ask questions about your health and past illnesses and dental problems. Be sure to tell your doctor or dentist if you use or have used tobacco in any form.

If your doctor suspects you may have oral cancer, one or more of the following tests may be used to find out if you have cancer and if it has spread.


If any abnormalities are discovered during the exam, a small tissue sample, or biopsy, usually is taken. This biopsy is important, as it is the only sure way to know if the abnormal area is cancer. A biopsy may be obtained by:

Brush biopsy or exfoliative cytology: This relatively new type of biopsy is painless and does not require anesthetic. The dentist or doctor rotates a small stiff-bristled brush on the area, causing abrasion or pinpoint bleeding. Cells from the area are collected and examined under a microscope by a pathologist. If results are inconclusive or show cancer, an incisional biopsy will be completed.

Incisional biopsy: This is the traditional, most frequently used type of biopsy. The doctor or dentist surgically removes part or all of the tissue where cancer is suspected. Usually, this procedure is completed in the doctor's office or clinic under local anesthesia. But if the tumor is inside the throat, the biopsy may be done in an operating room with general anesthesia.

Fine-needle-aspiration biopsy (FNA): This type of biopsy often is used if a patient has a lump in the neck that can be felt. In this procedure, a thin needle is inserted into the area. Then cells are withdrawn and examined under a microscope.

Mucosal staining: A blue dye called toluidine blue O is applied to the area where cancer is suspected. If any blue areas remain after rinsing, they probably will be investigated with a biopsy.

Chemiluminescent light: After you rinse your mouth with a mild acid solution, your mouth will be examined with a special light. Healthy cells do not reflect the light; cancerous cells do.

Imaging tests, which may include:

  • CT or CAT (computed axial tomography) scans
  • PET (positron emission tomography) scans
  • MRI (magnetic resonance imaging) scans
  • Chest and dental X-rays
  • Barium swallow: Also called an upper GI (gastrointestinal) series, this set of X-rays of the esophagus and stomach may be used to look for other cancers and determine how well you swallow.
  • Endoscopy

Oral Cancer Staging

If you are diagnosed with oral (mouth) cancer, your doctor will determine the stage of the disease. Staging is a way of classifying cancer by how much disease is in the body and where it has spread when it is diagnosed. This information helps the doctor treat the cancer. Once the staging classification is determined, the stage stays the same even if treatment is successful or the cancer spreads.

Disease stage is determined by the size of the primary tumor, how much it has invaded the tissues and whether the cancer has spread to the lymph nodes.

Health Tip

To keep your mouth healthy during cancer treatment, avoid commercial mouthwashes that contain a large amount of salt or alcohol.

Oral Cancer Stages

(Source: National Cancer Institute)

Stage 0: Cancer is "in situ," meaning it is isolated and has not traveled into a deeper layer of tissue or the lymph nodes, small almond-shape glands that help fight infection or trap tumor cells.

Stage I

  • Tumor is 2 centimeters (about ¾ inch) or smaller
  • Tumor has not spread to lymph nodes or other parts of the body

Stage II

  • Tumor is between 2 and 4 centimeters (from ¾ to 1½ inches)
  • Tumor has not spread to lymph nodes or other parts of the body

Stage III: Tumor is either:

  • Larger than 4 centimeters (1½ inches) or
  • Any size and has traveled to one lymph node on the same side of the head or neck. The lymph node with cancer measures 3 centimeters or less
  • Tumor has not spread to other parts of the body

Stage IV: Tumor is any size and has invaded deeply into muscle or facial skin or the jaws and has spread to:

  • More than one lymph node on the same side of the head or neck as the main tumor
  • Lymph nodes on one or both sides of the neck
  • Any lymph node that measures more than 6 centimeters (2½ inches)
  • Other parts of the body

Recurrent: The oral cancer has reappeared after it was treated. It may reappear in the oral cavity or another part of the body.

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Knowledge Center

Find the latest news and information about oral cancer in our Knowledge Center, including blog posts, articles, videos, news releases and more.