ear, nose, and throat disorders
Oral Squamous Cell Carcinoma
Introduction
Oral cancer refers to cancer occurring between the vermilion border of the lips and the junction of the hard and soft palates or the posterior one third of the tongue. Over 95% of people with oral squamous cell carcinoma smoke tobacco, drink alcohol, or both. Early, curable lesions are rarely symptomatic; thus, preventing fatal disease requires early detection by screening. Treatment is with surgery, radiation, or both, although surgery plays a larger role in the treatment of most oral cavity cancer. The overall 5-year survival rate (all sites and stages combined) is>50%. (See also Overview of Head and Neck Tumors .) Oral squamous cell carcinoma affects about 35,000 people in the US each year ( General reference ). In the US, 3% of cancers in men and 2% in women are oral squamous cell carcinomas, most of which occur after age 50. As with most head and neck sites, squamous cell carcinoma is the most common oral cancer. Thechief risk factorsfor oral squamous cell carcinoma are Smoking (especially>2 packs/day) Alcohol use Risk increases dramatically when alcohol use exceeds 6 oz of distilled liquor, 15 oz of wine, or 36 oz of beer/day. The combination of heavy smoking and alcohol abuse is estimated to raise the risk 100-fold in women and 38-fold in men. Squamous cell carcinoma of the tongue may also result from any chronic irritation, such as dental caries, overuse of mouthwash, chewing tobacco, or the use of betel quid. Oral human papillomavirus (HPV), typically acquired via oral-genital contact, may have a role in the etiology of some oral cancers; however, HPV is identified in oral cancer much less often than it is in Oropharyngeal Squamous Cell Carcinoma , and its presence in resected tissue does not necessarily imply causation. About 40% of intraoral squamous cell carcinomas begin on the floor of the mouth or on the lateral and ventral surfaces of the tongue. About 38% of all oral squamous cell carcinomas occur on the lower lip; these are usually solar-related cancers on the external surface. 