Cancer begins when normal cells change and grow uncontrollably, forming a mass called a tumor. A tumor can be cancerous or benign. A cancerous tumor is malignant, meaning it can spread to other parts of the body. A benign tumor means the tumor will not spread.
Cancer of the oral cavity and cancer of the oropharynx are two of the most common types of cancer that develop in the head and neck region, a grouping called head and neck cancer. The oral cavity includes the lips; lining of the lips and cheeks, called the buccal mucosa; gingiva, which is the upper and lower gums; front two-thirds of the tongue; floor of the mouth under the tongue; hard palate or the roof of the mouth; and the retromolar trigone, the small area behind the wisdom teeth. The oropharynx begins where the oral cavity stops. It includes the soft palate at the back of the mouth, the part of the throat behind the mouth, the tonsils, and the base of the tongue. The oral cavity and oropharynx, along with other parts of the head and neck, contribute to our ability to chew, swallow, breathe, and talk.
More than 90% of oral and oropharyngeal cancers are squamous cell carcinoma, meaning they begin in the flat, squamous cells found in the lining of the mouth and throat. The most common locations for cancer in the oral cavity are the tongue, tonsils, oropharynx, gums, and floor of the mouth.
Oral - Normal Lip TissueClick to Enlarge
Oral cavity - Squamous Cell CarcinomaClick to Enlarge
These images used with permission by the College of American Pathologists.
Although oral cancer and oropharyngeal cancer are commonly combined using one phrase, it is important to identify exactly where the cancer began because there are differences in treatment between the two locations.
Looking for More of an Overview?
If you would like additional introductory information, explore these related items. Please note these links take you to other sections on Cancer.Net:
- ASCO Answers Fact Sheet: Read a one-page fact sheet (available as a PDF) that offers an easy-to-print introduction to this type of cancer.
- Cancer.Net en Español: Read about oral and oropharyngeal cancer in Spanish. Infórmase sobre cáncer oral y orofaríngeoen español.