Head and neck cancer
The term head and neck cancers refers to a group of cancers found in the headand neck region. This includes tumors found in the oral cavity (mouth), theoropharynx (which includes the back one-third of the tongue, the back of thethroat and the tonsils); the nasopharynx (which includes the area behind thenose); the hypopharynx (lower part of the throat), and the larynx (voice box,located in front of the neck, in the region of the Adam's apple). The most frequently occurring cancers of the head and neck area are oral cancers and laryngeal cancers. Almost half of all the head and neck cancers occur in the oral cavity, and a third of the cancers are found in the larynx. By definition,the term "head and neck cancers" usually excludes tumors that occur in the brain.
Although the exact cause for these cancers is unknown, tobacco is regarded asthe single greatest risk factor: 75-80% of the oral and laryngeal cancer cases occur among smokers. Heavy alcohol use has also been included as a risk factor. In rare cases, irritation to the lining of the mouth, due to jagged teeth or ill-fitting dentures, has been known to cause oral cancer. Exposure toasbestos appears to increase the risk of developing laryngeal cancer.
In the case of lip cancer, just like skin cancer, exposure to sun overa prolonged period has been shown to increase the risk. In the Southeast Asian countries (India and Sri Lanka), chewing of betel nut has been associatedwith cancer of the lining of the cheek. An increased incidence of nasal cavity cancer has been observed among furniture workers, probably due to the inhalation of wood dust. A virus (Epstein-Barr) has been shown to cause nasopharyngeal cancer.
Head and neck cancers are one of the easiest to detect. The early signs can be both seen and felt. The signs and symptoms depend on the location of the cancer:
- Mouth and oral cavity: a sore that does not heal within two weeks, unusual bleeding from the teeth or gums, a white or red patch in the mouth, a lump or thickening in the mouth, throat, or tongue.
- Larynx: persistent hoarseness or sore throat, difficulty breathing, or pain.
- Hypopharynx and oropharynx: difficulty in swallowing or chewing food, ear pain.
- Nose, sinuses, and nasopharyngeal cavity: pain, bloody discharges from the nose, blocked nose, and frequent sinus infections that do not respondto standard antibiotics.
Specific diagnostic tests used depend on the location of the cancer. The first step in diagnosis is a complete and thorough examination of the oral and nasal cavity, using mirrors and other visual aids. The tongue and the back of the throat are examined as well. Any suspicious looking lumps or lesions are examined with fingers (palpation). In order to look inside the larynx, the doctor may sometimes perform a procedure known as laryngoscopy. The doctor may order blood or other immunological tests. These tests are aimed at detecting antibodies to the Epstein-Barr virus, which has been known to cause cancer ofthe nasopharynx.
X rays of the mouth, the sinuses, the skull, and the chest region may be required. Imaging techniques such as a computed tomography scan (CT scan); Ultrasonograms or an MRI (magnetic resonance imaging) may be used to get detailed pictures of the areas inside the body.
When a sore does not heal or a suspicious patch or lump is seen in the mouth,larynx, nasopharynx, or throat, a biopsy may be performed to rule outthe possibility of cancer. The biopsy is the most definitive diagnostic toolfor detecting the cancer. If cancerous cells are detected in the biopsied sample, the doctor may perform more extensive tests in order to find whether, and to where, the cancer may have spread.
The cancers can be treated successfully if diagnosed early. The choice of treatment depends on the size of the tumor, its location, and whether it has spread to other parts of the body. Surgery, radiation and chemotherapy, are themost common mods of treatment. Surgery is generally recommended for small tumors. If the cancer cannot be removed by surgery, radiotherapy is used alone.After aggressive surgery and radiation, rehabilitation is often necessary andis an essential part of the treatment. The patient may experience difficulties with swallowing, chewing, and speech and may require a team of health careworkers, including speech therapists, prosthodontists, occupational therapists etc.
With early detection and immediate treatment, survival rates can be dramatically improved. For lip and oral cancer, if detected at its early stages, almost 80% of the patients survive five years or more. Cancers of the nasal cavityoften go undetected until they reach an advanced stage. If diagnosed at theearly stages, the five-year survival rates are 60-70%. In cancer of the oropharynx, 60-80% of the patients survive five years or more if the cancer is detected in the early stages. Patients who are diagnosed with early stage cancers that have originated in the nasopharynx have an excellent chance of a complete cure (almost 95%). Similarly, small cancers of the larynx have an excellent five-year survival rate of 75-95%. However, in all of the head and neck cancers, the survival rates drop dramatically as the cancer advances.
Refraining from the use of all tobacco products (cigarettes, cigars, pipe tobacco, chewing tobacco), consuming alcohol in moderation, and practicing good oral hygiene are some of the measures that one can take to prevent head and neck cancers. Since there is an association between excessive exposureto the sun and lip cancer, people who spend a lot of time outdoors in the sunshould protect themselves from the sun's harmful rays. Regular physical examinations, or mouth examination by the patient himself, or by the patient's doctor or dentist, can help detect oral cancer in its very early stages.