Home > Encyclopedia of Nursing & Allied Health > Oral Cancer

Definition

Oral cancer refers to malignancies in the oral cavity (mouth) and the oropharynx. The oral cavity includes the lips, buccal mucosa (lining of the lips and cheeks), the hard palate, floor of the mouth, teeth, front two-thirds of the tongue, and gingiva (gums). The oropharynx includes the tonsils, soft palate, back third of the tongue, and the back of the throat.

Description

In the United States, oral cancer is diagnosed in approximately 30,000 patients each year and is responsible for about 8,000 deaths. Oral cancer is the sixth most frequently occurring cancer, and the most common sites of oral cavity cancers are the floor of the mouth and the tongue. In the oropharynx the most common sites of cancerous tumors are the tonsils and base of the tongue.

The economic and social impact of this disease is great. Oral cancer may result in serious long-term disabilities such as loss of speech, hearing, salivary, and chewing functions, as well as pain and disfigurement resulting from head and neck surgery.

Causes and symptoms

Nearly three-quarters of all oral cancers are related to tobacco use—either cigarette, pipe, or cigar smoking, or the use of smokeless tobacco products such as snuff. Tobacco-specific nitrosamines are the carcinogens (cancer-causing substances) implicated in the development of oral cancers. Chronic alcohol consumption is linked to oral cancers, and the use of alcohol and tobacco together poses a greater risk than using either one alone.

Exposure to asbestos or radiation increases the risk of developing oral cancers, and exposure to sunlight is a risk factor for cancer of the lips. A high-fat diet that is also low in fruits, vegetables, and other sources of vitamins A and C has been linked to development of oral cancers.

Age, gender, and race affect the risk of developing oral cancers. Oral cancer usually occurs among older adults because they have longer exposure to lifestyle and environmental risk factors. Oral cancer occurs 2.5 times more often in males than females, and blacks are affected more often than whites. The higher rate of oral cancer among black men is attributed to lifestyle, such as nutritional status, tobacco, and alcohol use, rather than genetic differences. Recent research on tobacco and alcohol use, however, has demonstrated comparable rates of oral cancer among blacks and whites.

The signs and symptoms of oral cancer depend upon the site of the tumor. Certain types of lesions in the oral cavity have the potential to become cancerous. Leukoplakias (white lesions) and erythroplakia (red lesions) that do not resolve within two weeks should be evaluated by a healthcare professional. Other possible signs or symptoms include:

• sore throat, hoarseness, or sensation that something is caught in the throat
• lump or thickening in the oral cavity
• difficulty chewing, eating, or swallowing
• difficulty moving the tongue or jaw
• numbness, weakness, or altered sensation in the mouth or tongue
• swelling of the jaw, mouth, or tongue
• changes in hearing, smell, or taste
• changes in the fit or feel of dentures or dental appliances
• abnormal odor or discharge from nose, ears, or mouth
• lesions, sores, or thickened patches that do not readily heal or resolve

Diagnosis

An examination to screen for oral cancer may be made by a physician, dentist, or dental hygienist. Though regular self-examination—with attention to inspection for lumps, thickenings, whitish patches, or sores—may detect some oral cancers, it is not a substitute for a thorough professional examination. An oral examination, performed by a physician or dentist using a mirror and lights, identifies abnormalities in the oral cavity. The physician will also palpate the throat, neck, and head for lumps or thickenings. X rays of the mouth, performed by a radiological technologist, may be used to examine suspicious areas.

When an abnormal area is detected in the oral cavity, the definitive diagnostic technique is biopsy— removal of all or part of the suspicious area for examination under the microscope by a pathologist. Biopsy is usually performed by an oral surgeon or an ear, nose, and throat specialist, also known as an otolaryngologist. Since squamous cells line the oral cavity, nearly all oral cancers are squamous cell carcinomas.

Staging

Staging refers to the process of determining the extent to which the cancer has metastasized (spread). Since treatment depends upon the stage of the oral cancer, additional diagnostic tests may be performed. These include imaging studies such as dental x rays and CT scans, and lymph node biopsy. Cancers of the oral cavity are identified as Stages I through IV and recurrent. Stage I cancers are less than three-quarters of an inch (2 centimeters) in size and have not spread to local lymph nodes. Stage II cancers are between three-quarters and one and one-half inches (2-4 centimeters) and have not metastasized to local lymph nodes. Stage III cancers are larger than one and one-half inches (4 centimeters), or are cancers of any size that have spread to a single lymph node on the same side of the neck as the cancer. Stage IV cancers have one or more of the following characteristics:

• spread to surrounding oral cavity tissue
• metastasized to more than one lymph node on the same side of the neck as the cancer
• metastasized to lymph nodes on both sides of the neck
• widespread metastasis throughout the body

Recurrent oral cancers are those that have returned following treatment. Recurrences may present in the oral cavity or elsewhere on the body.

Treatment

Treatment depends upon the location and stage of the cancer, as well as the age and overall health of the patient. It generally consists of a combination of surgery to remove as much of the cancer as possible and radiation and/or adjuvant chemotherapy (anticancer drugs) to kill any remaining cancer cells. Drugs called radiosensitizers are sometimes used to render cancer cells more sensitive to radiation. Most oral cancers are treated with surgery and fractionated (small, measured doses) radiation therapy. Another treatment that is presently being tested is hyperthermia. Since cancer cells are more sensitive to heat than normal cells, hyperthermia treatment involves heating the body in order to kill cancer cells.

Surgical treatment and radiation of the lips and oral cavity may produce disfigurement and difficulty with activities such as eating and talking. Patients recovering from treatment may benefit from rehabilitation with a

speech therapist and support from social workers or other mental health professionals.

Prognosis

The prognosis for patients with oral cancer depends, again, upon the location and stage of the cancer, as well as the patient's age, overall health and effectiveness of treatment. Generally, oral cancers detected early, such as Stage I cancers, have the best prognoses. Patients who have had oral cancers are at increased risk for developing another cancer of the mouth, head, or neck; for this reason, all patients require vigilant, regular follow up. Patients who stop smoking or using tobacco products and alcohol also have better outlooks than those who do not.

Health care team roles

Patients with oral cancers may be cared for by oral surgeons, otolarynogologists, oncologists, surgical and oncology nurses, laboratory and radiological technologists, speech therapists, and mental health professionals. Health educators and behavior modification specialists may be involved in assisting patients with smoking cessation or recovery from alcohol dependency.

Patient education

The objectives of education are to prevent patients from smoking or using tobacco products, and to encourage smokers to quit. Participation in smoking cessation programs should be encouraged, and patients should be informed about the health risks of excessive alcohol consumption. Patient teaching also should describe the role of environmental carcinogens such as asbestos, radiation, and sun exposure in the development of oral cancers.

Prevention

Since tobacco products and alcohol abuse are associated with more than 75% of oral cancers, health education efforts to prevent their use could sharply reduce the incidence of oral cancers. Regular examinations by a dentist or physician are vital for early detection of oral cancers.

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KEY TERMS

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Adjuvant therapy—Treatment involving radiation, chemotherapy (anticancer drug treatment), or a combination of both.

Biopsy—Surgical removal and microscopic examination of living tissue for diagnostic purposes.

Carcinogen—Any substance or agent capable of causing cancer.

Chemotherapy—Systemic treatment of cancer with synthetic drugs that destroy the tumor either by inhibiting the growth of cancerous cells or by killing them.

Malignant—Cancerous.

Metastasize—The spread of cancer cells from a primary site to distant parts of the body.

Oncologist—A physician who specializes in cancer medicine.

Pathologist—A person who specializes in the diagnosis of disease by studying cells and tissues under a microscope.

Radiation therapy—Treatment using high energy radiation from X-ray machines, cobalt, radium, or other sources.

Stage—A term used to describe the size and extent of spread of cancer.

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Barbara Wexler