Overview

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

  • Lips
  • Gums
  • Tongue
  • Inner lining of the cheeks
  • Roof of the mouth
  • Floor of the mouth

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 cancer grouped in a category called head and neck cancers. Mouth cancer and other head and neck cancers are often treated similarly.

Mayo Clinic's approach

Symptoms

Signs and symptoms of mouth cancer may include:

  • A sore that doesn't heal
  • A sore that bleeds
  • A growth, lump or thickening of the skin or lining of your mouth
  • Loose teeth
  • Poorly fitting dentures
  • Tongue pain
  • Jaw pain or stiffness
  • Difficult or painful chewing
  • Difficult or painful swallowing
  • Sore throat

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.

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.

Causes

Mouth cancer occurs when cells on your lips or in your mouth develop changes (mutations) in their DNA. These mutations allow cancer 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

Prevention

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, limit yourself to one drink a day if you're a woman or two drinks a day if you're a man.
  • Eat a variety of fruits and vegetables. Choose a diet rich in fruits and vegetables. The vitamins and antioxidants found in fruits and vegetables may help reduce your risk of mouth cancer.
  • 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.