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Mouth (Oral)

The mouth is also called the oral cavity. It is necessary for talking, eating, chewing and swallowing.
This information should not be used to diagnose yourself or in place of a doctor's care.
Diagnosis & staging

The mouth includes:

  • Lips.
  • Gums.
  • Front two-thirds of your tongue (the part you can move).
  • Hard palate (the front, hard part in the roof of your mouth).
  • Floor of your mouth.
  • Lining of your cheeks.
  • Salivary glands (make the saliva that keeps your mouth moist and helps digest food).

Mouth cancer may also be called oral cancer, oral cavity cancer, tongue cancer, or lip cancer.

What are the signs and symptoms of mouth cancer?

The most common symptom is an ulcer (a sore) or swelling in your mouth that does not heal.

Other symptoms include:

  • Lump, thickening or rough spot in your mouth that does not go away or is growing.
  • New, different coloured spots in your mouth or on your lips.  These may feel different.
    • White spots are called leukoplakia.
    • Red spots are called erythroplakia.
  • Pain, numbness, tenderness in your lips, mouth, jaw or ear.
  • Difficulty swallowing or chewing.
  • A change in the way your teeth fit together.
  • A change in your voice.

Your dentist will check your mouth for these signs each time you see them.  If any of these symptoms last for more than two weeks, please see your doctor, nurse practitioner or dentist.

If you have any signs or symptoms that you are worried about, please talk to your family doctor or nurse practitioner.

How is mouth cancer diagnosed?

Tests that may help diagnose mouth cancer include:

  • Biopsy: This is when a doctor takes a sample of your tissue. A specialty doctor (pathologist) then examines the tissue for cancer. 
  • Imaging: to see the tumour and if cancer has spread
    • CT (Computed Tomography) scan
    • MRI (Magnetic Resonance Imaging)
    • PET (Positron Emission Tomography) scan

For more information on tests used to diagnose cancer, see BC Cancer Library screening and diagnosis pathfinder.

What are the types of mouth cancer?

  • The most common type of mouth cancer is squamous cell carcinoma. This cancer starts in the cells that line your mouth.
  • Less common types are adenocarcinomas, sarcomas and melanomas.

What are the stages of mouth cancer?

Staging describes the cancer. Staging is based on how much cancer is in the body, where it was first diagnosed, if the cancer has spread and where it has spread to.

The stage of the cancer can help your health care team plan your treatment. It can also tell them how your cancer might respond to treatment and the chance that your cancer may come back (recur). 

Mouth cancer staging

  • Stage 1: The tumour is 2 cm (0.75 inches) or less.
  • Stage 2: The tumour is more than 2 cm but less than 4 cm (1.5 inches).
  • Stage 3: One of the following:
    • The tumour is more than 4 cm.
    • The cancer has spread to one lymph node in the neck on the same side as the tumour. Lymph node is 3 cm (about 1 inch) or smaller
  • Stage 4:  Lip cancer – tumour has grown into nearby structures.
  • Stage 4A: Oral cavity – tumour has grown into nearby structures such as bone, deep muscles of the tongue, or skin of the face.
  • Stage 4B: Tumour has grown into the base of the skull or is growing around the carotid artery.
For more information about staging, see About Cancer.

What are the grades of mouth cancer?

The grade of the cancer describes how different the cancer cells look from normal cells and how fast the cancer cells are growing.  

A pathologist will give the cancer a grade after looking at the cells under a microscope. Mouth cancer can be grade 1, 2, 3 or 4. The lower the number, the lower the grade. 

Low grade: cells are abnormal but look a lot like normal cells.  Low grade cancers usually grow slowly and are less likely to spread.

High grade: cells are abnormal and do not look like normal cells. High grade cancers usually grow more quickly and are more likely to spread.

The grade of the cancer can help your health care team plan your treatment.


What is the treatment for mouth cancer?

Cancer treatment may be different for each person. It depends on your particular cancer. Your treatment may be different from what is listed here.

Treatment for mouth cancer depends on the type of cancer, the size and stage of the cancer, how old you are, and if you have any other medical conditions.


  • Localized tumours (tumours that have not spread) are usually removed by surgery or laser excision.
  • Often used to treat early stage tumours.
  • Usually chosen if the tumour can be removed and you will still have good mouth function.  Mouth surgery may remove bone and skin.  In this case, you may need reconstruction (rebuild part of your mouth).  A surgeon may need to take skin, muscle or bone from other parts of your body for reconstruction.
  • More advanced cancers are often treated with surgery and radiation therapy.

Radiation Therapy (high energy x-rays that kill or shrink cancer cells)

  • Often used when surgery would mean major reconstruction of your mouth.
  • You may get radioactive implants (treat only the main tumour site) or external beam radiation (treats main tumour site and nearby lymph nodes).
  • External beam radiation therapy lasts 2-5 weeks.
  • If your tumour has a high chance of spreading to lymph nodes in your neck, you may get radiation therapy to your neck. You may get this even if there is no sign of cancer in your lymph nodes. 
  • BC Cancer radiation therapy

Systemic therapy (chemotherapy)

  • Often given with radiation therapy.
  • May be used to relieve pain or symptoms of advanced mouth cancer.  
  • BC Cancer systemic therapy

What is the follow-up after treatment?

  • Follow-up testing and appointments are based on the type and stage of your cancer.
  • Follow-up after treatment for mouth cancer
  • These are guidelines written for your doctor, nurse practitioner or specialist. You can look at them to see what appointments and tests you might need after treatment.
  • It is very important that you are followed carefully by an oncologist or otolaryngologist for two years after your treatment.
  • After treatment, you will likely need to see a dietitian, a physiotherapist and a speech language pathologist. They will help you with side effects from treatment.
  • It is important you take care of your mouth and teeth after radiation therapy.  Please read our Dry Mouth and Mouth Pain handout for tips on how to care for your mouth and teeth.
  • Life after Cancer has information on issues that cancer survivors may face.
More information

What causes mouth cancer and who gets it?

These are some of the risk factors for this cancer. Not all of these risk factors may cause this cancer, but they may help the cancer start growing.

  • Using tobacco, in any form. The longer you use it, the greater your risk of getting mouth cancer.
  • Drinking a lot of alcohol.
  • Drinking a lot of alcohol and using tobacco at the same time.
  • Breathing in second-hand smoke.
  • Unprotected exposure to strong sunlight over long periods of time increases the risk of lip cancer.
  • Chewing betel or areca nuts. These are found in paan, chaalia, gutka and naswar.
  • Eating a diet that does not include and a lot of fruits and vegetables.
  • Chronic irritation from dentures that do not fit well.
  • Chronis gum disease (periodontal disease)
  • Having a Human Papillomavirus (HPV) infection.

Statistics on mouth cancer

Note: Available statistics do not have information about the inclusion of transgender and gender diverse participants. It is unknown how these statistics apply to transgender and gender diverse people. Patients are advised to speak with their primary care provider or specialists about their individual considerations and recommendations.

Can I help prevent mouth cancer?

Most mouth cancers can be prevented. Using tobacco and drinking too much are the major risk factors for getting this cancer.

Here are some things you can do to lower your risk of mouth cancer:

  • Do not smoke: If you smoke, stop. Also, try to avoid breathing in cigarette smoke. Even if you have been using tobacco for many years, quitting will lower your cancer risk. Support is available to help you successfully quit.
  • Do not drink too much alcohol: Not drinking alcohol at all will lower your cancer risk the most.
  • If you have been cured of mouth cancer, you should still stop using tobacco and alcohol. Using tobacco and drinking alcohol will increase your risk of getting another cancer.
  • Eat healthy, nutritious foods:
  • Visit your dentist regularly.
  • Wear sunscreen: If you work outdoors or are outside a lot, wear sunscreen on your lips. Also, wear a hat with a large brim.

Is there screening for mouth cancer?

  • See your dentist regularly. This is the best way to screen for mouth cancers.

Where can I find more information?

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