Oral Cancers Health Article

Definition

Cancer of the mouth or the oral cavity and the oropharynx is referred to as oral cancer.

Description

Oral cavity describes a broad array of parts within the mouth including the lips, lining on the lips and cheeks referred to as buccal mucosa, teeth, tongue, floor of the mouth under the tongue, hard palate (which is the firm bony top of the mouth) and the gums. The oropharynx includes the back of the tongue, the soft palate, and the tonsils (fleshy part on either side of the mouth). There are glands through out the oral cavity that produce saliva that keep the mouth moist, known as salivary glands. The secretions from these glands called saliva aid in digesting the food.

Under normal circumstances, the oral cavity and oropharynx are comprised of several types of tissues and cells, and tumors can develop from any of these cells. These tumors may either be benign (they do not spread to the adjoining tissues), or the tumor may invade other tissues of the body. Any potential growth of a benign tumor into a cancerous (malignant) tumor is referred to as a precancerous condition. Leukoplakia or erythroplakia, which are abnormal areas in the oral cavity, may develop in many of the oral cancers as the first stage. Leukoplakia is a white area that is just a benign condition, but about 5% of leukoplakias develop into cancer. Erythroplakia is a red bumpy area that bleeds when scraped, and has the potential to develop into cancer within 10 years if not treated.

Benign tumors are those that are not invasive and thus incapable of spreading. Examples of benign tumors of the oral cavity include keratocanthoma, leiomyoma, osteochondroma, neurofibroma, papilloma, schwannoma and odontogenic tumors. These tumors are generally harmless and can be surgically removed. Recurrence of these tumors after surgical removal is very rare.

More than 90% of malignant tumors of the oral cavity and oropharynx are squamous cell carcinoma also referred to as squamous cell cancer. Squamous cells form the lining of the oral cavity and oropharynx and morphologically, they appear flat and scale-like. When the cancer cells appear just in the lining of the oral cavity, it marks the initial stages of the squamous cell cancer and is referred to as carcinoma in situ. Appearance of cancer cells on deeper layers of the oral cavity or oropharynx refers to invasive squamous cell cancer which is a more serious condition. Verrucous carcinomas are a type of squamous cell carcinoma that seldom metastasize but can spread to the adjoining tissues. Thus a surgeon might suggest removal of a wide area of surrounding tissues in addition to removing the cancerous tissue. The chances of developing a second cancer in the oral region (oral cavity or pharynx) at a later time during the life period is about 10-40%, thus necessitating thorough follow-up examinations. In addition, refraining from smoking and drinking will help to prevent the disease recurrence. Among other types of malignant tumors of the oral cavity are salivary gland cancers and Hodgkin's disease. The former affects the salivary glands present throughout the mucosal lining of the oral cavity and oropharynx. The latter is the cancer that develops in the lymphoid tissue of the tonsils and base of the tongue.

Demographics

The statistical survey on oral cancers reveals that more men are affected by the disease than women. The American Cancer Society has estimated that about 30, 100 new cases oral cavity and pharyngeal cancers will be diagnosed in the year 2001. Of these, predictions are that 20, 200 will be men and 9, 900 women. The estimates also suggest that about 7, 800 people will die of cancer of oral cavity or oropharynx. The incidence and the mortality rate have been directed toward a decreasing trend in the last 20 years. Studies on patient survival show that about 82% suffering from oral cancer, survive for more than a year, about 51% survive for five years and about 48% for 10 years.

Certain geographic differences affect the incidence of oral cavity cancers. Hungary and France show higher incidence of the disease as compared to the United States. However, the disease is much less common in Japan and Mexico suggesting that environmental factors do play a key role in the outcome of the disease.

About 15% of patients diagnosed with either oral or oropharynx cancer are more often known to develop cancer of the adjoining organs (or tissues) including larynx, oesophagus or lung. The chances of developing a second cancer in the oral region (oral cavity or pharynx) for survivors, at a later time during the life period is about 10% to 40%. Thus, a person once diagnosed with cancer of oral cavity has to undergo through follow up examinations for the rest of their lives, even if cured completely. In addition, restraining from smoking tobacco and drinking alcohol will greatly facilitate in preventing the disease occurrence as tobacco use has been shown to be responsible for 90% of tumors of oral cavity in men and 60% among women.