What is mouth cancer? A Mayo Clinic expert explains

Learn more about mouth cancer, also called oral cancer, from oncologist Katharine Price, M.D.

Hello, I'm Dr. Katharine Price, an oncologist at Mayo Clinic. In this video, we'll cover the basics of oral cancer: What is it? Who gets it? The symptoms, diagnosis and treatment. Whether you're looking for answers for yourself or someone you love, we're here to give you the best information available. Oral cancer, also called mouth cancer, forms in the oral cavity, which includes all parts of your mouth that you can see if you open wide and look in the mirror. Your lips, gums, tongue, cheeks, roof or floor of the mouth. Oral cancer forms when cells on the lips or in the mouth mutate. Most often they begin in the flat, thin cells that line your lips and the inside of your mouth. These are called squamous cells. Small changes to the DNA of the squamous cells make the cells grow abnormally. These mutated cells accumulate, forming a tumor that grows in the mouth and often spread to lymph nodes in the neck. Oral cancer is curable if detected at an early stage. And like other cancers, a large amount of effort has been dedicated to determining causes and improving treatments.

The average age of those diagnosed with oral cancer is 63. Just over 20% of cases occur in patients younger than 55. However, it can affect anyone. There are several known risk factors that could increase your risk of developing oral cancer. If you use any kind of tobacco, cigarettes, cigars, pipes, chewing tobacco, and others, you're at a greater risk. Heavy alcohol use also increases the risk. Those with HPV, human papillomavirus, have a higher chance of developing oral cancer as well. Other risk factors include a diet that lacks fruit and vegetables, chronic irritation or inflammation in the mouth, and a weakened immune system.

Oral cancer can present itself in many different ways, which could include: a lip or mouth sore that doesn't heal, a white or reddish patch on the inside of your mouth, loose teeth, a growth or lump inside your mouth, mouth pain, ear pain, and difficulty or pain while swallowing, opening your mouth or chewing. If you're experiencing any of these issues and they persist for more than two weeks, see a doctor. They'll be able to rule out more common causes first, like an infection.

To determine if you have oral cancer, your doctor or dentist will usually perform a physical exam to inspect any areas of irritation such as sores or white patches. If they suspect something is abnormal, they may conduct a biopsy where they take a small sample of the area for testing. If oral cancer is diagnosed, your medical team will then determine how far along the cancer is, or the stage of the cancer. The stage of the cancer ranges from 0 to 4 and helps your doctor counsel you on the likelihood of successful treatment. In order to determine the stage, they may perform an endoscopy, where doctors use a small camera to inspect your throat, or they may order imaging tests, like CT scans, PET scans, and MRIs, to gather more information.

What your treatment plan looks like will depend on your cancer's location and stage, as well as your health and personal preferences. You may have just one type of treatment or you may need a combination of cancer treatments. Surgery is the main treatment for oral cancer. Surgery generally means removing the tumor and possibly lymph nodes in the neck. If the tumor is large, reconstruction may be required. If the tumor is small and there's no evidence of spread to lymph nodes, surgery alone may be enough treatment. If the oral cancer has spread to lymph nodes in the neck or is large and invading different areas of the mouth, more treatment is required after surgery. This could include radiation, which uses high-power beams of energy to target and destroy the mutated cancerous cells. Sometimes chemotherapy is combined with the radiation. Chemotherapy is a powerful cocktail of chemicals that kills the cancer. Immunotherapy, a newer treatment which helps your immune system attack the cancer, is also sometimes used.

Learning you have oral cancer can be difficult. It can leave you feeling helpless. But remember, information is power when it comes to your health. This disease is survivable - now more than ever. Be informed. Take control of your health. And partner with your medical team to find a treatment that's right for you. If you'd like to learn even more about mouth cancer, watch our other related videos or visit mayoclinic.org. We wish you well.

Mouth cancer refers to cancer that develops in any of the parts that make up the mouth (oral cavity). Mouth cancer can occur on the:

  • Lips
  • Gums
  • Tongue
  • Inner lining of the cheeks
  • Roof of the mouth
  • Floor of the mouth (under the tongue)

Cancer that occurs on the inside of the mouth is sometimes called oral cancer or oral cavity cancer.

Mouth cancer is one of several types of cancers grouped in a category called head and neck cancers. Mouth cancer and other head and neck cancers are often treated similarly.


Signs and symptoms of mouth cancer may include:

  • A lip or mouth sore that doesn't heal
  • A white or reddish patch on the inside of your mouth
  • Loose teeth
  • A growth or lump inside your mouth
  • Mouth pain
  • Ear pain
  • Difficult or painful swallowing

When to see a doctor

Make an appointment with your doctor or dentist if you have any persistent signs and symptoms that bother you and last more than two weeks. Your doctor will likely investigate other more common causes for your signs and symptoms first, such as an infection.

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Mouth cancers form when cells on the lips or in the mouth develop changes (mutations) in their DNA. A cell's DNA contains the instructions that tell a cell what to do. The mutations changes tell the cells to continue growing and dividing when healthy cells would die. The accumulating abnormal mouth cancer cells can form a tumor. With time they may spread inside the mouth and on to other areas of the head and neck or other parts of the body.

Mouth cancers most commonly begin in the flat, thin cells (squamous cells) that line your lips and the inside of your mouth. Most oral cancers are squamous cell carcinomas.

It's not clear what causes the mutations in squamous cells that lead to mouth cancer. But doctors have identified factors that may increase the risk of mouth cancer.

Risk factors

Factors that can increase your risk of mouth cancer include:

  • Tobacco use of any kind, including cigarettes, cigars, pipes, chewing tobacco and snuff, among others
  • Heavy alcohol use
  • Excessive sun exposure to your lips
  • A sexually transmitted virus called human papillomavirus (HPV)
  • A weakened immune system


There's no proven way to prevent mouth cancer. However, you can reduce your risk of mouth cancer if you:

  • Stop using tobacco or don't start. If you use tobacco, stop. If you don't use tobacco, don't start. Using tobacco, whether smoked or chewed, exposes the cells in your mouth to dangerous cancer-causing chemicals.
  • Drink alcohol only in moderation, if at all. Chronic excessive alcohol use can irritate the cells in your mouth, making them vulnerable to mouth cancer. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women of all ages and men older than age 65, and up to two drinks a day for men age 65 and younger.
  • Avoid excessive sun exposure to your lips. Protect the skin on your lips from the sun by staying in the shade when possible. Wear a broad-brimmed hat that effectively shades your entire face, including your mouth. Apply a sunscreen lip product as part of your routine sun protection regimen.
  • See your dentist regularly. As part of a routine dental exam, ask your dentist to inspect your entire mouth for abnormal areas that may indicate mouth cancer or precancerous changes.

April 30, 2024

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