Cancers can occur in any tissues of the oral cavity, including the front two thirds of the tongue, the gums ("gingiva"), the lining of the inside of the cheeks and lips (" buccal mucosa"), the floor of the mouth (under the tongue), the hard palate and the small area behind the wisdom teeth ("retromolar trigone"). Oral cancers are most common in people who chew tobacco or smoke pipes.

Finding a lump in the lip or gums, having a sore in the mouth that won't heal, or new bleeding or pain in the mouth should all prompt a visit to the doctor. Another common sign of a cancer of the mouth is that dentures may cease fitting well.

The doctor will do a full exam of the mouth and will use a mirror to get a good look at less accessible areas. Local anesthesia will be used to "numb" any area from which the doctor wishes to remove a tissue sample. ("Biopsy" is the taking of a surgical tissue sample for examination by a pathologist.)

 For the discussion below, you may wish to refer to Learning - The Mouth.

When a cancerous tumor is found, the doctor will want to "stage" the disease. Both the choice of treatment and its effectiveness are related to the stage of the tumor.

Stage I

• The cancer is no more than 2 centimeters (about 1 inch) and it has not spread to lymph nodes in the neck

Stage II

• The cancer is more than 2 centimeters, but less than 4 centimeters, and has not spread to lymph nodes.

Stage III

Either...

• The cancer is more than 4 centimeters, or
• The cancer is any size but has spread to just one lymph node on the same side of the neck as the tumor (node<3 cm)

Stage IV

Either...

• The cancer has spread to tissues around the oral cavity
• The cancer is any size and has spread to more than one lymph node on the same side of the neck, to lymph nodes on both sides of the neck, or to any lymph node that measures more than 6 centimeters
• The cancer has spread to other parts of the body.

Treatment

The primary treatments for oral cancers are surgery and/or radiation therapy. In surgery, the doctor will remove the tumor together with some surrounding normal tissue. Such "radical" surgery is standard in most cancer treatment since the doctors need to be as certain as possible that all the local disease is removed. In some cases, local treatment can be accomplished employing trans-oral laser microsurgery. This technique may allow the surgeon to sacrifice less normal tissue.

If there is reason to suspect spread to local lymph nodes, some form of "lymph node dissection" may be carried out. The nature and extent of lymph node removal will vary from removal of just a few nodes near the area of the tumor, to "radical neck dissection" where nearly all neck nodes are removed.

Radiation therapy uses high-energy x-rays to kill cancer cells.The radiation may come from a machine outside the body ("external beam therapy") or from radioactive materials that are put into the tissues through thin plastic tubes or needles (internal radiation therapy, including "bachytherapy"). Those who stop smoking before radiation therapy have a better chance of surviving longer.

It is important that the head and neck cancer patient who needs radiation be prepared by an oncologic dentist.
(See Dentistry in Head and Neck Cancer)

In some cases, local treatments (surgery and/or radiation) may be supplemented by "systemic" treatment with chemotherapy. Chemotherapy is administered by mouth or by injection, introducing medicines that are able to travel throughout the body and potentially destroy any cancer cells that "broke away" and escaped the local treatment. When this therapy is given after local treatment as a supplement, it is known as "adjuvant" chemotherapy. Treatments given to shrink a tumor before local surgery or radiation are used is called, "neo-adjuvant" therapy.