It is a type of head and neck cancer and is often treated similarly to other head and neck cancers.
Mouth cancer mostly happens after the age of 40, and the risk is more than twice as high in men as it is in women.
Signs and symptoms of mouth cancer
Oral cancer can appear as a lesion or tumor anywhere in the mouth.
In the early stages, there are often no signs or symptoms, but smokers and heavy drinkers should have regular checkups with the dentist, as they may identify early signs.
Signs and symptoms include:
- Patches on the lining of the mouth or tongue, usually red or red and white in color
- Mouth ulcers or sores that do not heal
- Swelling that persists for over 3 weeks
- A lump or thickening of the skin or lining of the mouth
- Pain when swallowing
- Loose teeth with no apparent reason
- Poorly fitting dentures
- Jaw pain or stiffness
- Sore throat
- A sensation that something is stuck in the throat
- Painful tongue
- Hoarse voice
- Pain in the neck or ear that does not go away
Having any of these symptoms does not mean that a person has mouth cancer, but it is worth checking with a doctor.
What does mouth cancer look like?
Warning: The following images are graphic:
Mouth cancer - premalignant lesions
Mouth cancer - red premalignant lesions
Close up image of cancer on the tongue.
Mouth cancer on the tongue
Causes of mouth cancer
Cancer results when a genetic mutation instructs cells to grow without control. Untreated, oral cancer will start in one part of the mouth, then spread to other parts of the mouth, to the head and neck, and the rest of the body. Mouth cancers typically start in the squamous cells that line the lips and the inside of the mouth. This is called squamous cell carcinoma.
The exact cause of the mutations is unknown, but there is evidence that certain risk factors increase the chance of mouth cancer developing.
Risk factors for mouth cancer
Smoking is a significant risk factor for mouth cancer.
Tobacco and alcohol use are prominent risk factors for mouth cancer.
Smokers are three times more likely than nonsmokers to develop mouth cancer, and people who smoke and drink alcohol have up to 30 times higher risk than those who do not smoke and drink.
Other risk factors include:
- Ultraviolet exposure on the lips, from the sun, sunlamps, or sunbeds
- A diet rich in red meat, processed meat, and fried foods
- Gastro-esophageal reflux disease (GERD), a digestive condition where acid from the stomach leaks back up to the gullet
- Human papillomavirus (HPV) infection
- Prior radiation treatment, or radiotherapy, in the head, neck, or both
- Regularly chewing betel nuts, a popular habit in some parts of Southeast Asia
- Exposure to certain chemicals, especially asbestos, sulfuric acid, and formaldehyde
The United Kingdom's National Health Service (NHS) note that there is a "small chance" that broken or jagged teeth increase the risk of mouth cancer. They encourage people to follow good oral and dental hygiene practices, including regular brushing, to reduce the risk.
The dentist may be the first person to spot signs of mouth cancer.
A biopsy may be carried out, where a small sample of tissue is taken to check for cancerous cells. Sometimes a "brush biopsy" is used initially; this where cells are painlessly collected by brushing them to one side.
If mouth cancer is diagnosed, the next task is to determine the stage of the cancer.
- Endoscopy, where a lighted scope is passed down the patient's throat to see how far the cancer has spread
- Imaging tests, such as X-ray, Computed Tomography (CT) scans, and Magnetic Resonance Imaging (MRI) Staging the cancer will inform treatment options and help predict prognosis
Cancers are often staged in the following way:
- Stage 1: The tumor is under 1 inch across and has not reached nearby lymph nodes
- Stage 2: The tumor measures 1 to 2 inches and has not reached nearby lymph nodes
- Stage 3: Either the tumor is over 2 inches across but has not spread, or it has spread to one nearby lymph node on the same side of the neck as the tumor, and the lymph node is no more than 1 inch across
- Stage 4: The cancer affects tissues around the mouth, lips, and possibly nearby lymph nodes; or it has spread to the rest of the body
A person who is diagnosed with stage 1 oral or pharyngeal cancer has an 83 percent chance of surviving for longer than 5 years. Around 31 percent of cases are diagnosed at this stage.
For those whose cancer spreads to other parts of the body, the chance of surviving more than 5 years is 38 percent.
Treatment depends on the location and stage of the cancer, and the patient's general health and personal preferences. A combination of treatments may be necessary.
Surgical removal of the tumor involves taking out the tumor and a margin of healthy tissue around it. A small tumor will require minor surgery, but for larger tumors, surgery may involve removing some of the tongue or the jawbone.
If the cancer has spread to the lymph nodes in the neck, the cancerous lymph nodes and related tissue in the neck will be surgically removed.
If surgery significantly changes the appearance of the face, or the patient's ability to talk, eat, or both, reconstructive surgery may be necessary. This involves using transplanted grafts of skin, muscle, or bone from other parts of the body. Dental implants may be needed.
Oral cancers are especially sensitive to radiation therapy, which 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 delivers radiation from outside, while in brachytherapy, radioactive seeds and wires can be placed near the cancer inside the body.
Brachytherapy is often used to treat patients with early stages of cancer of the tongue.
Radioactive wires or needles are stuck directly into the tumor, releasing a dose of radiation into the tumor. The patient is usually under general anesthetic. A course normally lasts from 1-8 days.
A person with early-stage mouth cancer may only need radiation therapy, but it can also be combined with surgery, chemotherapy, or both, to prevent the cancer from returning.
Radiation therapy may remove cancer if a patient is in the early stages of oral cancer.
Adverse effects of radiation therapy in the mouth include:
- Tooth decay
- Mouth sores
- Bleeding gums
- Jaw stiffness
- Skin reactions, as with a burn
Chemotherapy, radiotherapy, and surgery are three treatment options.
Widespread cancer may be treated with chemotherapy as well as radiation therapy, especially if there is a significant chance of the cancer returning.
Chemotherapy involves using powerful medicines that damage the DNA of the cancer cells, undermining their ability to reproduce.
Chemotherapy medications can sometimes damage healthy tissue.
The following adverse effects may occur:
- Hair loss
- Weakened immune system, increasing the risk of infection
These effects usually go away after finishing treatment.
Targeted drug therapy
Targeted drug therapy uses drugs known as monoclonal antibodies to change aspects of cancer cells that help them grow.
Cetuximab, or Erbitux, is used for some head and neck cancers. Targeted drugs may be combined with radiotherapy or chemotherapy.
The following mild adverse effects are possible:
- Inflammation of the eyes, or conjunctivitis
Around 3 percent of patients will have an allergic reaction to cetuximab.
Complications of mouth cancer
Complications include difficulty swallowing (dysphagia). Swallowing is normally an automatic process, but surgery or radiotherapy may affect the action of the tongue, mouth, or throat.
Dysphagia can lead to malnutrition and food going down the wrong way, leading to choking, lung infections, or aspiration pneumonia.
If tests show that particles of food are entering the patients' lungs, a short-term feeding tube may be directly connected to the stomach, while the patient learns exercises that improve their swallowing. A person who continues to have problems may need to follow a special diet.
Speaking problems are common, but a speech therapist can teach some exercises that develop vocal movements.
Depression, irritability, frustration, and anxiety may occur. Joining a support group or online forum can be helpful, providing an opportunity to meet people with similar experiences.
Prevention of oral cancer
A number of lifestyle changes can reduce the risk of mouth cancer; these include:
- Quitting or avoiding tobacco
- Consuming alcohol in moderation or not at all
- Avoid excessive sun exposure and using sunscreen on the lips
- Avoiding junk foods, saturated fats, and processed meats
Evidence suggests that the chance of developing cancer of all types is lower among those who exercise regularly and follow a healthy diet, with plenty of fruit, vegetables, fish oil, olive oil, whole grains, and small amounts of lean animal or plant-based protein.