Oral Cancer

content developed with: http://www.mdanderson.org/

About 34,000 people are diagnosed with cancers of the mouth and oropharynx (the part of the throat just behind the mouth) in the United States each year. Fortunately, cases of these cancers and deaths have been decreasing over the past 30 years.

These cancers are more common in other countries, especially Hungary and France, and some 480,000 new cases are diagnosed worldwide each year. Although the exact causes of these cancers are unknown, alcohol and tobacco use are major risk factors. More recently, the human papilloma virus has been found to cause cancers of the tonsil and the back portion of the tongue.

More than half of patients are diagnosed after the cancer has spread to other areas in the body. Chances of successfully treating mouth and oropharynx cancer are highest when it is found early.

This section contains more information on:

  • Need-to-know anatomy
  • Causes
  • Risk factors
  • Need-to-know anatomy

    The mouth and oropharynx are important for talking, swallowing, eating, and breathing. The oropharynx is the middle section of the pharynx (throat), which is a 5-inch tube that begins behind the nose and ends at the trachea (windpipe) and esophagus (a tube that connects the throat to the stomach). Air travels through the pharynx to the trachea, and food travels through the pharynx to the esophagus.

    Mouth cancer is most commonly found in the tongue, the floor of the mouth, and the lips. It can also begin in the gums, salivary glands, the lining of the lips and cheeks, the roof of the mouth, or the area behind the wisdom teeth.

    Oropharynx cancer, which is sometimes called oropharyngeal cancer, starts in the area just behind the mouth. It also occurs in the back of the tongue, the back of the mouth and the uvula, the tonsils, and the back and side walls of the throat.

    Almost all the cancers of the mouth and oropharynx occur in squamous cells, which line the mouth and oropharynx. These are called squamous cell carcinomas.

    Not all tumors are cancerous. Some are benign (noncancerous) and some are precancerous, meaning they have the potential to develop into cancer.


    Like other cancers, mouth and oropharynx cancer develops when cells grow out of control. The exact cause of most mouth and oropharynx cancer is not known, but it is known that tobacco damages DNA, the genetic material within cells that helps control cell repair and growth.

    The combination of tobacco and alcohol is especially dangerous to DNA. Alcohol makes it easier for chemicals, including tobacco, to enter the cells and cause DNA malfunction. Then the abnormal cells may grow to form a tumor, or cancer.

    Human papillomavirus infection, which causes almost all types of cervical cancer, may increase the risk of developing oral cancer. HPV is found in 20 percent to 50 percent of mouth and oropharynx cancers.

    Risk factors

    Although doctors do not know what causes some cases of mouth and oropharynx cancer, there are factors that make it more likely a person will get the disease.


    Ninety percent of people with mouth and oropharynx cancer use tobacco. As the length of time and the amount used increase, so does the likelihood of contracting the disease.

    Specifically, pipe smoking increases the risk for cancer of the lip and the soft palate (the back of the mouth). People who use smokeless tobacco—chewing tobacco or snuff—are more likely to develop cancer of the gums, cheek, and lips. Living with a smoker or working in a smoking environment can cause secondhand or passive smoking, which may also increase risk.


    People who drink alcohol and smoke are six times as likely to get mouth and oropharynx cancer as people who do not drink alcohol. About 80 percent of people with these cancers are heavy drinkers, consuming more than 21 alcoholic drinks each week. The combination of tobacco and alcohol is particularly dangerous.

    Other risk factors

    Other factors can increase the risk of getting mouth and oropharynx cancer, including:

    • Infection with human papillomavirus. Cancers associated with HPV most commonly occur in white males in their 50s.
    • Gender: About two thirds of patients are men.
    • Race: The risk is higher for blacks who smoke and consume alcohol.
    • Age: These cancers are more common in people over 45.
    • Prolonged sun exposure (lip cancer)
    • Long-term irritation caused by ill-fitting dentures
    • Poor nutrition, especially a diet low in fruits and vegetables
    • Immunosuppressive drugs
    • Previous head and neck cancer
    • Radiation exposure
    • Lichen planus, a disease that often affects the cells that line the mouth
    • Drinking maté, a beverage common in South America made from a type of holly tree
    • Chewing quids of betel, a stimulant common in Asia
    • Last reviewed on 6/4/09

      U.S. News's featured content providers were not involved in the selection of advertisers appearing on this website, and the placement of such advertisement in no way implies that these content providers endorse the products and services advertised. Disclaimer and a note about your health.