Overview of Oral Cavity Cancer
The oral cavity includes the lip, the alveolar ridge (area immediately behind the top front teeth), the retromolar trigone (small area behind the wisdom teeth), the floor of the mouth (area under the tongue), the buccal mucosa (lining inside the lips and cheeks), the tongue, and the hard palate.
Approximately 30,000 new cases of oral cavity cancer occur each year. Studies show there is a strong link between smoking and alcohol consumption and disease development. Other factors include genetic susceptibility, diet (vitamin A deficiency), viruses (herpes simplex virus type 1), chronic irritants (e.g., poor dental hygiene), and syphilis. Pathologically, the most common tumor type found in the oral cavity is squamous cell carcinoma.
In the Unites States, cancer of the lip occurs in approximately 4000 people each year. Most cases occur on the lower lip and as many as 90 percent of cases occur in men. Risk factors include smoking (cigarettes and pipes) and sun exposure. Squamous cell carcinoma of the lip is the most common type, although basal cell carcinoma also can occur. The typical symptom is an ulcerative lesion or an exophytic (outward growing) growth on the lower lip.
Cancers of the alveolar ridge (area immediately behind the top front teeth) and retromolar trigone (small area behind the wisdom teeth) account for approximately 10 percent of all oral cancers, or about 4000 cases per year. Four times as many men are affected than women. Presenting symptoms usually include pain that is worsened by chewing. Other symptoms include loose teeth and intermittent bleeding. Nearly all of these cancers are squamous cell carcinomas.
Floor-of-the-mouth cancer usually develops around the age of 60. These cancers account for 10 to 15 percent of all oral cavity cancers—about 4000 to 6000 cases per year. They are approximately 3 times more common in men and typically present as infiltrating lesions that are very painful.
Cancers of the tongue occur in approximately 6000 individuals per year and account for about 15 percent of all oral cavity cancers. The average age at diagnosis is 60, and men are diagnosed three times more often than women. Tongue cancers, like most other oral cavity cancers, can be infiltrative or exophytic. In most cases, the primary presenting symptom is pain. Cancers of the tongue have a high risk of early lymph node involvement and spread to lymph nodes on both sides (bilateral) in as many as 25 percent of patients.
Tumors of the hard palate account for 5 percent of all oral cavity malignancies—about 1500 cases per year. They occur in men 8 times more often than in women. Squamous cell carcinoma of the hard palate accounts for about 50 percent of cases and tumors of the minor salivary glands (e.g., adenoid cystic, adenocarcinoma) account for the remaining cases.
Cancer of the buccal mucosa (lining inside the lips and cheeks) accounts for approximately 2500 cases per year. These cancers are often exophytic in naturethey grow outward. The presenting symptoms are usually pain, followed by bleeding and difficulty chewing.