Oral Cancer Information

What is Oral Cancer?

Oral cancer begins in the mouth, also called the oral cavity. This region of the body includes the lips, the inside lining of the lips and cheeks (called the buccal mucosa), the teeth, the gums, most of the tongue, the bottom of the mouth, and the bony roof of the mouth, or hard palate.

In addition, cancer oral can also develop in the oropharynx, which is the part of the throat that is just behind the mouth. When cancer occurs here, it is called oropharyngeal cancer or throat cancer, and can include the back of the tongue, the back of the roof of the mouth, the tonsils, and the walls of the upper throat.

The oral cavity and oropharynx are key to the healthy functioning of the body. They help us breathe, eat, and speak. Salivary glands in the oral cavity start breaking down food as we chew, an essential part of digestion.

Cancer can develop in any part of the oral cavity. Because each part of the oral cavity is different, oral cancer encompasses a wide variety of cancer types that are treated in different ways.

Each year, there are about 34,000 new cases of oral cancer and oropharyngeal cancer in the United States. The most common site of oral cancer is the tongue, which accounts for 25% of all oral cancers. The tonsils, lips, and minor salivary glands each account for 10% to 15% of all oral cancers, and the remainder are found in the gums, the floor of the mouth, and other areas.

Types of Oral Cancer

There are several types of cancer that can begin in the oral cavity.

• Squamous cell carcinoma: More than 90% of cancers that occur in the oral cavity and oropharynx are squamous cell carcinoma. Normally, the throat and mouth are lined with so-called squamous cells, which are flat and arranged in a scale-like way. Squamous cell carcinoma means that some squamous cells are abnormal.
• Verrucous carcinoma: About 5% of all oral cavity tumors are verrucous carcinoma, which is a type of very slow-growing cancer made up of squamous cells. This type of oral cancer rarely spreads to other parts of the body, but can invade the tissue surrounding the site of origin.
• Minor salivary gland carcinomas: This category includes several kinds of oral cancer that can develop on the minor salivary glands, which are found throughout the lining of the mouth and throat. These types include adenoid cystic carcinoma, mucoepidermoid carcinoma, and polymorphous low-grade adenocarcinoma.
• Lymphomas: Oral cancers that develop in lymph tissue, which is part of the immune system, are known as lymphomas. The tonsils and base of the tongue both contain lymphoid tissue. See our pages on Hodgkin lymphoma and non-Hodgkin lymphoma for cancer information related to lymphomas in the oral cavity.
• Benign oral cavity and oropharyngeal tumors: Several types of non-cancerous tumors and tumor-like conditions can arise in the oral cavity and oropharynx. Sometimes, these conditions may develop into cancer. For this reason, benign tumors, which usually don’t recur, are often surgically removed. The types of benign lesions include:
  • Eosinophilic granuloma
  • Fibroma
  • Granular cell tumor
  • Karatoacanthoma
  • Leiomyoma
  • Osteochondroma
  • Lipoma
  • Schwannoma
  • Neurofibroma
  • Papilloma
  • Condyloma acuminatum
  • Verruciform xanthoma
  • Pyogenic granuloma
  • Rhabdomyoma
  • Odontogenic tumors (lesions that begin in tooth-forming tissues)
• Leukoplaka and erythroplakia: These non-cancerous conditions mean that there are certain types of abnormal cells in the mouth or throat. With leukoplakia, a white area can be seen, and with erythroplakia, there is a red area, flat or slightly raised, that often bleeds when scraped. Both conditions may be precancerous; that is, they can develop into different types of cancer. When these conditions occur, a biopsy or other test is done to determine whether the cells are cancerous.

Most leukoplakia is benign; about 25% of cases of leukoplakia are either cancerous when first discovered or become precancerous. Erythroplakia is usually more serious, with about 70% of cases cancerous either at the time of diagnosis or later.

Next Topic: Oral Cancer Risk Factors