Mouth cancer

What is mouth cancer?

Mouth cancer is a cancer that can develop in any part of the mouth, including the tongue, the gums, the palate (roof of the mouth), under the tongue, the skin lining the mouth or the lips.

Mouth cancer is also sometimes called oral cancer. Worldwide it is the sixth most common cancer. Although mouth cancer is uncommon in the UK, it seems to be getting much more common: the number of cases doubled in the 20 years from 1994 to 2014.

There are around 7,500 cases diagnosed each year in the UK. It is twice as common in men as it is in women. It is rare in people aged under 40 but it is becoming more common. Many cases are diagnosed by dentists rather than doctors, often during a dental check-up. See the separate leaflet called Cancer for more general information about cancer.

What does mouth cancer look like?

The most common mouth cancer symptoms are a sore or ulcer in the mouth that does not heal and pain in the mouth that does not go away.

In many cases, changes are seen in the mouth before the cancer develops. This means that early treatment of these changes will actually prevent a cancer developing.

Other symptoms

Other signs that indicate mouth cancer include:

• White patches anywhere in your mouth (leukoplakia).

• Red patches anywhere in your mouth (erythroplakia).

• A lump on the lip or tongue, or in the mouth or throat.

• Unusual bleeding or numbness in the mouth.

• Pain when chewing or swallowing.

• A feeling that something is caught in the throat.

• Unusual bleeding or numbness in the mouth.

• Loose teeth, or dentures feeling uncomfortable and not fitting properly.

• A change in your voice, or speech problems.

• Weight loss.

• A lump in the neck.

• If the cancer spreads to other parts of the body, various other symptoms can develop.

All of these symptoms can be due to other conditions, so tests are needed to confirm the diagnosis.

When to see a doctor

What causes mouth cancer?

A cancer starts from one cell becoming abnormal. The exact reason why a cell becomes cancerous (malignant) is not fully understood. It is thought that something changes or damages some of the genes in the cell. This makes the cell behave abnormally and reproduce out of control. See the separate leaflet called Causes of Cancer for more details.

Some people develop mouth cancer for no apparent reason. However, certain risk factors increase the chance that mouth cancer may develop. These include:

• Smoking. Mouth cancer is just one cancer which has a much higher incidence in smokers than in non-smokers.

• Smokeless tobacco is used widely worldwide and is also known to cause mouth cancer. It is particularly common in South Asian countries. There are many different forms - for example:

  • Paan.

  • Betel quid.

  • Areca nut.

  • Gutkha - this is particularly popular in children because of its sweet taste.

  • Chaalia.

  • Naswar.

  • Toombak.

• Alcohol. Drinking a lot of alcohol can increase your risk of developing mouth cancer. It seems to increase your risk even more if you also use tobacco (smoked or chewed).

• The human papillomavirus (HPV) also increases your risk of mouth cancer:

  • Most people with HPV will not develop mouth or any other cancer.

  • There is an immunisation against HPV. It is not known if being immunised against HPV will reduce your risk of developing mouth cancer but it seems likely. You can find out more in the separate leaflet called Human Papillomavirus Immunisation (HPV).

• Poor dental hygiene.

• Dietary factors (eating a well-balanced diet - high in whole fruits, vegetables and fish and low in processed meats, rice and refined grains - may reduce the risk of oral cancer).

• There are some conditions affecting the mouth, such as leukoplakia and erythroplakia, which can increase the risk of a cancer developing.

Diagnosing mouth cancer

Your healthcare professional may suspect mouth cancer if you have a lesion in your mouth (such as a sore, an ulcer or a lump) which has not healed for 3 weeks or more.

To confirm the diagnosis

It is likely that you will need a biopsy. A biopsy is a procedure involving a small sample of tissue being removed from a part of the body. The sample is then looked at under the microscope to look for abnormal cells. Results of a biopsy can take a week or two. You can find out more in the separate leaflet called Biopsy.

Assessing the extent and spread (staging)

If you are found to have mouth cancer then further tests may be done. For example, more biopsy samples may be taken, this time from the nearby lymph glands (lymph nodes) by using a fine needle. This is to assess if any cancer cells have spread to the lymph glands.

Other tests may be arranged to see if the cancer has spread to other parts of the body. For example, a computerised tomography (CT) scan, a magnetic resonance imaging (MRI) scan, or other tests.

This assessment is called staging of the cancer. The aim of staging a cancer is to find out:

• How much the tumour has grown in the mouth.

• Whether the cancer has spread to local lymph nodes near your mouth.

• Whether the cancer has spread to other areas of the body (metastasised).

See the separate leaflet called Stages of Cancer for more information.

Treating mouth cancer

Mouth cancer treatments which may be considered include radiotherapy, surgery and chemotherapy. The treatment advised will usually depend on various factors such as the exact site and extent of the cancer and your general health.

You should have a full discussion with a specialist who knows your situation. They will be able to give the pros and cons, likely success rate, possible side-effects and other details about the possible treatment options for your type of cancer.

You should also discuss with your specialist the aims of treatment. For example:

Treatment to cure the cancer

There is a good chance of a cure if it is treated in the early stages. Many cases are diagnosed at an early stage. This is because early mouth cancers are more easily detected than cancers deeper inside the body.

(Doctors tend to say remission rather than use the word cured. Remission means there is no evidence of cancer following treatment. If you are in remission, you may well be cured. However, in some cases cancer can return months or years later. This is why doctors are sometimes reluctant to use the word cured.)

Treatment to control the cancer

If a cure is not likely, with treatment it is often possible to limit the growth or spread of the cancer so that it progresses less rapidly. This may keep you free of symptoms for some time.

Treatment to ease symptoms

For example, if a cancer is advanced then you may require painkillers or other treatments to help keep you free of pain or other symptoms. Some treatments may be used to reduce the size of a cancer, which may ease symptoms such as pain or difficulty with swallowing.

Surgery

The most common treatment is surgery. The type of operation depends on the size of the cancer and its site. The operation may be to remove the cancer and some of the surrounding normal tissue.

Sometimes surgery is aimed at curing the cancer by removing it all. Sometimes surgery is used to relieve symptoms if the cancer is at an advanced stage (palliative surgery). The operations are all done whilst you are asleep under a general anaesthetic.

Laser surgery may sometimes be used to remove small mouth cancers. This may be combined with a light-sensitive medicine in treatment known as photodynamic therapy (PDT).

Sometimes a special type of surgery called micrographic surgery, or Mohs' surgery, is used for cancers on the lip. In this surgery, the surgeon removes the cancer in very thin layers and the tissue that has been removed is examined under a microscope during the operation. This technique makes sure that all the cancer cells are removed and only a very small amount of healthy tissue is removed.

Radiotherapy

Radiotherapy is a treatment which uses high-energy beams of radiation which are focused on malignant (cancerous) tissue. This kills cancer cells, or stops cancer cells from multiplying. See the separate leaflet called Radiotherapy for more details.

Two types of radiotherapy are used for mouth cancer: external and internal.

• External radiotherapy. Radiation is targeted on the cancer from a machine. (This is the common type of radiotherapy which is used for many types of cancer.)

• Internal radiotherapy (brachytherapy). This treatment involves placing small radioactive wires next to the cancer for a short time. These are then removed.

Chemotherapy

Chemotherapy is a treatment which uses anti-cancer medicines to kill cancer cells, or to stop them from multiplying. Chemotherapy may be used in conjunction with radiotherapy or surgery. Chemotherapy may also be advised if the cancer has spread to other areas of the body.

Other treatments

Newer treatments are being used in research for the treatment of mouth cancer:

Targeted therapy is a type of chemotherapy that only affects or targets cancer cells:

• The advantage it is hoped to have over conventional chemotherapy is that it shouldn't harm healthy cells.

• Epidermal growth factor receptor monoclonal antibody (EGFR mAb) is one form of targeted therapy. Cetuximab is an EGFR mAb.

• Tyrosine kinase inhibitors (TKIs) are another.

Immunotherapy is treatment that aims to boost the body's own immune system to destroy the cancer cells. It is also sometimes called biological therapy:

• Recombinant interleukin (rIL-2) is a form of immunotherapy.

It is not known yet whether being treated with a targeted therapy or immunotherapy improves the outcome for people with mouth cancer.

How to prevent mouth cancer

It is sensible advice to avoid the main risk factors for developing mouth cancer:

• Tobacco use; so stopping smoking, or using any other smokeless tobacco product is recommended.

• Alcohol use is known to increase your risk, so reducing to recommended safe limits, or stopping drinking alcohol is also advised.

• Poordental hygiene. See a dentist regularly as this will support good dental hygiene and ensure any potential problems are spotted quickly.

What is the outlook?

If a mouth cancer is diagnosed and treated at an early stage then there is a good chance of a cure. A cure is less likely if the cancer has spread.

The treatment of cancer is a rapidly developing area of medicine. There are often new treatments being found and the information above on how you will do is very general. The specialist who knows you can give you more accurate information about how well your type and stage of cancer is likely to respond to treatment and your particular outlook (prognosis).