Oral cancer can appear anywhere in the mouth, including the inside of the cheeks and the gums. It is a type of head and neck cancer.
It often comes under the category of oral and oropharyngeal cancer. Oropharyngeal cancer affects the back of the mouth and the lining of the throat.
According to the American Cancer Society (ACS), around 53,000 Americans will receive a diagnosis of oral or oropharyngeal cancer in 2019.
The average age at diagnosis is 62 years old, but around 25% of cases happen before the age of 55, say the ACS. The disease is more likely to affect males than females.
In the early stages, there are often no signs or symptoms of oral cancer.
Smokers and heavy drinkers should have regular checkups with the dentist, as tobacco and alcohol are risk factors for mouth cancer.
The dentist may be able to spot any signs at an early stage.
Precancer
Signs that cancer could develop eventually include:
Leukoplakia: This is where there are white patches in the mouth that do not disappear when a person rubs them.
Oral lichen planus: This is where there are areas of white lines with a reddish border, possibly with ulceration.
Many oral lesions may be precancerous. They do not mean that someone has cancer, but people should speak to their doctor about any changes that occur in the mouth.
Monitoring changes may help spot mouth cancer in the early stages when it is easier to treat.
Cancer
If cancer develops, a person may notice:
- patches on the lining of the mouth or tongue, usually red or red and white
- bleeding, pain, or numbness in the mouth
- mouth ulcers or sores that do not heal
- a lump or thickening of the gums or lining of the mouth
- loose teeth with no apparent reason
- poorly fitting dentures
- swelling in the jaw
- a sore throat or feeling that something is stuck in the throat
- a hoarse voice
- difficulty chewing or swallowing
- difficulty moving the tongue or jaw
Having any of these symptoms does not mean that a person has mouth cancer, but it is worth checking with a doctor.
Treatment will depend on:
- the location, stage, and type of cancer
- the individual's overall health
- personal preferences
There are a number of options, as we describe here.
Surgery
A doctor may recommend surgery to remove the tumor and a margin of healthy tissue around it.
Surgery may involve removing:
- part of the tongue
- the jawbone
- lymph nodes
If the procedure significantly changes the person's appearance or their ability to talk or eat, they may need reconstructive surgery.
Radiation therapy
Oral cancers are sensitive to radiation therapy. This treatment uses beams of high energy X-rays or radiation particles to damage the DNA inside the tumor cells, destroying their ability to reproduce.
External beam radiation: A machine targets the affected area with radiation beams.
Brachytherapy: The surgeon will use radioactive needles to deliver radiation to the tumor inside the body. A doctor may recommend this for people with early stage tongue cancer.
Adverse effects of radiation therapy in the mouth may include:
- tooth decay
- mouth sores
- bleeding gums
- jaw stiffness
- fatigue
- skin reactions, such as a burn
Treatment will likely be more effective in people who do not smoke or have already quit.
A person with early stage mouth cancer may only need radiation therapy, but a doctor can recommend combining it with other treatments to reduce the risk of cancer progressing or recurring.
Find out more about radiation therapy here.
Chemotherapy
If cancer is widespread, a doctor may recommend combining chemotherapy with radiation therapy.
Chemotherapy involves using powerful medicines that damage the DNA of the cancer cells. The drugs undermine the cells' ability to reproduce and spread.
Chemotherapy medications destroy cancer cells, but they can sometimes damage healthy tissue, too. This can lead to severe adverse effects.
These effects may include:
- fatigue
- nausea and vomiting
- hair loss
- a weakened immune system and increased risk of infection
These effects usually go away after a person finishes their treatment.
Learn more about chemotherapy.
Hyperthermia therapy
In this emerging technique, a doctor will heat the area above normal temperature to damage and kill cancer cells.
This therapy method can also increase the sensitivity of the cancer cells to radiation therapy.
The stage of cancer refers to how far it has spread.
In the earliest stages, there may be precancerous cells that could eventually become cancerous.
This is sometimes called stage 0 cancer, or carcinoma in situ. A doctor may advise a person to stop smoking and to monitor for further changes.
- Localized cancer only affects one area and has not spread to other tissues.
- Regional cancer has spread to nearby tissues.
- Distant cancer has spread to other parts of the body, including, possibly, the lungs or liver.
Untreated, oral cancer may start in one part of the mouth, then spread to other parts of the mouth. It may also spread to the head, neck, and the rest of the body.
The treatment options and outlook will depend, to some extent, on the stage of cancer.
Learn more about carcinoma in situ.
Mouth cancer and its treatment can lead to a range of complications.
Complications after surgery include the risk of:
- bleeding
- infection
- pain
- difficulty eating and swallowing
Long term problems may include the following:
Narrowing of the carotid artery: This can result from radiation therapy and may lead to cardiovascular problems.
Dental problems: These can develop if surgery changes the shape of the mouth and jaw.
Dysphagia, or difficulty swallowing: This can make it hard to eat and may increase the risk of inhaling food, and subsequent infections.
Speech problems: Changes to the tongue, lips, and other oral features can affect speech.
Mental health issues: Depression, irritability, frustration, and anxiety may arise.
Joining a local or online support group can be helpful. This contact offers the opportunity to meet people with similar experiences.
Cancer happens when a genetic change in the body results in cells growing without control. As these unwanted cells continue to grow, they form a tumor. In time, the cells can migrate to other parts of the body.
Around 90% of mouth cancers are squamous cell carcinoma. They start in the squamous cells that line the lips and the inside of the mouth.
Risk factors
Doctors do not know why these changes happen, but some risk factors seem to increase the chance of mouth cancer developing.
There is evidence that the following factors increase the risk:
- smoking or chewing tobacco
- using snuff, which comes from tobacco
- regularly chewing betel nuts, a popular habit in parts of Southeast Asia
- excessive alcohol consumption
- human papillomavirus (HPV) infection, and especially HPV type 16
- a previous history of a head and neck cancer
Learn more here about HPV infection.
Other factors that may increase the risk of mouth cancer include:
- ultraviolet (UV) exposure to the lips from the sun, sunlamps, or sunbeds
- gastroesophageal reflux disease (GERD)
- previous radiation therapy in the head, neck, or both
- exposure to certain chemicals, especially asbestos, sulfuric acid, and formaldehyde
- having a long standing wound or chronic trauma, for example, from jagged teeth
- drinking very hot mate tea, popular in South America
Following a healthful diet that contains plenty of fresh fruit and vegetables may reduce the risk.
If a person has symptoms that could indicate mouth cancer, a doctor will:
- ask about their symptoms
- carry out a physical examination
- ask about their personal and family medical history
If mouth cancer is a possibility, they may also recommend a biopsy, he doctor takes a small sample of tissue to check for cancerous cells.
This may be a brush biopsy where the doctor collects cells painlessly using a special brush.
If the biopsy reveals mouth cancer, the next task is to determine the stage.
Tests to stage cancer include:
An endoscopy: The doctor will pass a thin tube with a light and small camera down the person's throat to see if cancer has spread and, if so, how far.
Imaging tests: An X-ray of the lungs, for example, will show if cancer has reached that area.
The outlook for a person with oral or oropharyngeal cancer will depend on the stage of cancer, where it occurs in the mouth, and other factors.
The following statistics from the ACS show the average likelihood a person has of surviving at least 5 years with mouth cancer.:
| Stage | Tongue | Lip | Floor of mouth |
| Local | 81% | 92% | 78% |
| Regional | 67% | 61% | 39% |
| Distant | 39% | 24% | 19% |
| Overall | 66% | 88% | 53% |
Apart from the stage of cancer, other factors affect a person's chance of a longer life, such as:
- their age
- their overall health
- the grade or type of cancer, as some are more aggressive than others
- their access to a range of treatment options
Smoking is a significant risk factor for mouth cancer.
To reduce the risk of mouth cancer, people should:
- avoid using any form of tobacco product
- avoid excessive alcohol consumption
- avoid chewing betel nut
- have a regular dental check
- monitor for changes in the mouth and see a doctor or dentist if any occur
- have the vaccination to protect against HPV
Doctors are finding evidence of a link between HPV and oropharyngeal cancer.
Click here to learn more about tonsil cancer, which also has HPV as a risk factor.