Cancers that are known collectively as head and neck cancers usually begin in the squamous cells that line the moist, mucosal surfaces inside the head and neck (for example, inside the mouth, the nose, and the throat). These squamous cell cancers are often referred to as squamous cell carcinomas of the head and neck. Head and neck cancers can also begin in the salivary glands, but salivary gland cancers are relatively uncommon.
Cancers of the head and neck are further categorized by the area of the head or neck in which they begin. These areas are described below.
Oral cavity: Includes the lips, the front two-thirds of the tongue, the gums, the lining inside the cheeks and lips, the floor (bottom) of the mouth under the tongue, the hard palate (bony top of the mouth), and the small area of the gum behind the wisdom teeth.
Pharynx: The pharynx (throat) is a hollow tube about 5 inches long that starts behind the nose and leads to the esophagus. It has three parts: the nasopharynx (the upper part of the pharynx, behind the nose); the oropharynx (the middle part of the pharynx, including the soft palate [the back of the mouth], the base of the tongue, and the tonsils); the hypopharynx (the lower part of the pharynx).
Larynx: The larynx, also called the voicebox, is a short passageway formed by cartilage just below the pharynx in the neck. The larynx contains the vocal cords. It also has a small piece of tissue, called the epiglottis, which moves to cover the larynx to prevent food from entering the air passages.
Paranasal sinuses and nasal cavity: The paranasal sinuses are small hollow spaces in the bones of the head surrounding the nose. The nasal cavity is the hollow space inside the nose.
Salivary glands: The major salivary glands are in the floor of the mouth and near the jawbone. The salivary glands produce saliva.
Alcohol and tobacco use (including smokeless tobacco, sometimes called “chewing tobacco” or “snuff”) are the two most important risk factors for head and neck cancers, especially cancers of the oral cavity, oropharynx, hypopharynx, and larynx. At least 75% of head and neck cancers are caused by tobacco and alcohol use. People who use both tobacco and alcohol are at greater risk of developing these cancers than people who use either tobacco or alcohol alone. Tobacco and alcohol use are not risk factors for salivary gland cancers.
Infection with cancer-causing types of human papillomavirus (HPV), especially HPV type 16, is a risk factor for some types of head and neck cancers, particularly oropharyngeal cancers that involve the tonsils or the base of the tongue.
Other risk factors for cancers of the head and neck include the following:
Paan (betel quid). Immigrants from Southeast Asia who use paan (betel quid) in the mouth should be aware that this habit has been strongly associated with an increased risk of oral cancer.
Preserved or salted foods. Consumption of certain preserved or salted foods during childhood is a risk factor for nasopharyngeal cancer.
Oral health. Poor oral hygiene and missing teeth may be weak risk factors for cancers of the oral cavity. Use of mouthwash that has a high alcohol content is a possible, but not proven, risk factor for cancers of the oral cavity.
Occupational exposure. Occupational exposure to wood dust is a risk factor for nasopharyngeal cancer. Certain industrial exposures, including exposures to asbestos and synthetic fibers, have been associated with cancer of the larynx, but the increase in risk remains controversial. People working in certain jobs in the construction, metal, textile, ceramic, logging, and food industries may have an increased risk of cancer of the larynx. Industrial exposure to wood or nickel dust or formaldehyde is a risk factor for cancers of the paranasal sinuses and nasal cavity.
Radiation exposure. Radiation to the head and neck, for noncancerous conditions or cancer, is a risk factor for cancer of the salivary glands.
Epstein-Barr virus infection. Infection with the Epstein-Barr virus is a risk factor for nasopharyngeal cancer and cancer of the salivary glands.
Ancestry. Asian ancestry, particularly Chinese ancestry, is a risk factor for nasopharyngeal cancer.
SYMPTOMS & SIGNS:
The symptoms of head and neck cancers may include a lump or a sore that does not heal, a sore throat that does not go away, difficulty in swallowing, and a change or hoarseness in the voice. These symptoms may also be caused by other, less serious conditions. It is important to check with a doctor or dentist about any of these symptoms. Symptoms that may affect specific areas of the head and neck include the following:
Oral cavity. A white or red patch on the gums, the tongue, or the lining of the mouth; a swelling of the jaw that causes dentures to fit poorly or become uncomfortable; and unusual bleeding or pain in the mouth.
Pharynx. Trouble breathing or speaking; pain when swallowing; pain in the neck or the throat that does not go away; frequent headaches, pain, or ringing in the ears; or trouble hearing.
Larynx. Pain when swallowing or ear pain.
Paranasal sinuses and nasal cavity. Sinuses that are blocked and do not clear; chronic sinus infections that do not respond to treatment with antibiotics; bleeding through the nose; frequent headaches, swelling or other trouble with the eyes; pain in the upper teeth; or problems with dentures.
Salivary glands. Swelling under the chin or around the jawbone, numbness or paralysis of the muscles in the face, or pain in the face, the chin, or the neck that does not go away.
To find the cause of the signs or symptoms of a problem in the head and neck area, a doctor evaluates a person’s medical history, performs a physical examination, and orders diagnostic tests. The exams and tests may vary depending on the symptoms. Examination of a sample of tissue under a microscope is always necessary to confirm a diagnosis of cancer.
If the diagnosis is cancer, the doctor will want to learn the stage (or extent) of disease. Staging is a careful attempt to find out whether the cancer has spread and, if so, to which parts of the body. Staging may involve an examination under anesthesia (in an operating room), x-rays and other imaging procedures, and laboratory tests. Knowing the stage of the disease helps the doctor plan treatment.
The treatment plan for an individual patient depends on a number of factors, including the exact location of the tumor, the stage of the cancer, and the person’s age and general health. Treatment for head and neck cancer can include surgery, radiation therapy, chemotherapy, targeted therapy, or a combination of treatments.
People who are diagnosed with HPV-positive oropharyngeal cancer may be treated differently than people with oropharyngeal cancers that are HPV-negative. Recent research has shown that patients with HPV-positive oropharyngeal tumors have a better prognosis and may do just as well on less intense treatment.
Regular follow-up care is very important after treatment for head and neck cancer to make sure that the cancer has not returned, or that a second primary (new) cancer has not developed. Depending on the type of cancer, medical checkups could include exams of the stoma, if one has been created, and of the mouth, neck, and throat. Regular dental exams may also be necessary.
From time to time, complete physical exam, blood tests, x-rays, and computed tomography (CT), positron emission tomography(PET), or magnetic resonance imaging (MRI) scans may be needed. The doctor may monitor thyroid and pituitary gland function, especially if the head or neck was treated with radiation. Also, the doctor is likely to counsel patients to stop smoking.