Head and Neck cancer

 Head and neck cancer is the term given to a variety of malignant tumors that develop in the

• oral cavity (mouth);
• pharynx (throat);
• paranasal sinuses (small hollow spaces around the nose lined with cells that secrete mucus);
• nasal cavity (airway just behind the nose);
• larynx ("Adam's apple" or voice box); and
• salivary glands (parotid, submanidular, sublingual glands that secrete saliva).
  

Many authorities also include skin tumors of the face and neck and tumors of the cervical lymph nodes. Excluding superficial skin cancers, but including cancer of the larynx and thyroid, it is conservatively estimated that about 60,000 people are diagnosed with head and neck cancer annually - about 5% of all cancers diagnosed in the United States. There are more than half a million survivors of oral cancer, head cancer, and neck cancer living in the United States today.

Anatomy of the head and neck

The head and neck can be divided into several different regions:

• nasopharynx: area behind the nose
• pharynx: hollow tube at the upper part of the throat that starts behind the nose, runs down to the neck, and becomes part of the esophagus, the tube that goes to the stomach
• oral cavity: lips, floor of mouth, tongue, buccal mucosa (lining inside the lips and cheeks), gingiva (gums) and hard palate (bony top of the mouth), salivary glands (parotid, submandibular and minor salivary glands)
• oropharynx: base of tongue, tonsillar region, soft palate and pharyngeal walls
• hypopharynx: bottom part of the throat
• larynx (voice box): supraglottic, glottic (vocal cords), and subglottic regions
• nasal cavity: paranasal sinuses (ethmoid and maxillary)

Risk Factors

Factors known to contribute to the risk of developing head and neck cancers include smoking (both tobacco and marijuana) or chewing tobacco and frequent alcohol use. Leukoplakia (white spots or patches in the mouth) also may be considered a risk factor, as this condition becomes cancerous in approximately one-third of patients.

Pathology
Most head and neck cancers are squamous cell carcinomas, tumors that develop in the tissue lining the hollow organs of the body. However, other tumor types also may be seen and include lymphoepithelioma, spindle cell carcinoma, verrucous cancer, undifferentiated carcinoma and cancers of the lymph nodes, called lymphoma (most often diffuse non-Hodgkins lymphoma).

Signs and Symptoms
Cancers of the head and neck are some of the few cancers for which a particular cause can often be identified. When examined, patients who report the symptoms described below commonly admit to being smokers and/or frequent consumers of substantial quantities of alcohol. In fact, some doctors candidly admit that it is quite rare to see patients with head and neck cancer who do not smoke or drink excessively.

The common symptoms of cancer of the head and neck include:

    persistent pain in the throat;
    pain or difficulty with swallowing;
    persistent hoarseness or a change in voice;
    pain in the ear; and
    bleeding in the mouth or throat.

Because about half of all head and neck cancers originate in the oral cavity, sores or lesions in the mouth can be warning signs. Two types of lesions that could be precursors to cancer are leukoplakia (white lesions) and erythroplakia (red lesions). Although less common than leukoplakia, erythroplakias have a much greater potential for becoming cancerous. Any white or red lesion that does not heal or disappear in 2 weeks should be evaluated by a physician and considered for biopsy.

Other possible signs/symptoms of oral cancer include:

    lump or thickening in oral soft tissues;
    soreness or feeling that something is stuck in the throat;
    difficulty chewing or swallowing;
    difficulty moving the jaw or tongue;
    numbness of the tongue or other parts of the mouth; and
    swelling of the jaw that causes dentures to fit poorly or become uncomfortable.

Anyone experiencing such symptoms for more than 2 weeks should see their physician as soon as possible for a thorough examination and laboratory tests. If a diagnosis cannot be obtained, your physician will refer you to a specialist.

Diagnosis
Establishing a diagnosis for head and neck cancers typically begins with an examination and biopsy of any identified suspected cancerous lesions or tumors. This involves extracting a piece of suspiciou s tissue and sending it to a laboratory for examination. In some cases the biopsy can be performed in the physician's office, although it is more common for the procedure to be done in an operating room under anesthesia.

Staging
Staging is the process of describing the extent to which cancer has spread from the site of its origin. It is used to assess a patient's prognosis and to determine the choice of therapy. The stage of a cancer is determined by the size and location in the body of the primary tumor, and whether it has spread to other areas of the body.

Staging involves using the letters T, N and M to assess tumors by:

    the size of the primary tumor (T);
    the degree to which regional lymph nodes (N) are involved. Lymph nodes are small organs located along the channels of the body's lymphatic system which store special cells that fight infection and other diseases); and
    the absence or presence of distant metastases (M) - cancer that has spread from the original (primary) tumor to distant organs or distant lymph nodes.

Each of these is categories is further classified with a number 1 through 4 to give the total stage. Thus a T1-N1-M0 cancer would describe a T1 tumor, N1 lymph node involvement, and no metastases.

Once the T, N and M are determined, a "stage" of I, II, III or IV is assigned:

    Stage I cancers are small, localized and usually curable.
    Stage II and III cancers typically are locally advanced and/or have spread to local lymph nodes.
    Stage IV cancers usually are metastatic (have spread to distant parts of the body) and generally are considered inoperable.

The staging system for head and neck cancers is a bit complicated. Though the nodal and metastasis staging systems are the same for all the different anatomical regions of the head and neck, the tumor staging systems are different. The nodal and metastasis staging systems are outlined below. Each region's tumor staging system is presented separately on one of the linked pages.

Cancer that returns or develops again after all visible evidence of a tumor has been eradicated through treatment is called recurrent disease. Disease that recurs in the area of the original or primary tumor is called locally recurrent; that which recurs as metastases is referred to as a distant recurrence. Distant recurrence is usually treated as Stage IV disease.

Types
There are several different types of head and neck cancer, categorized according to the specific tissue or organ where the cancer originates ... from cancerous lesions on the lower lip to paranasal sinus tumors deep within the skull. Click on one of the links below for detailed information on each type of cancer, including staging and treatment guidelines.

Tumors of the Nasal Cavity and Paranasal Sinuses
The nasal cavity is the passageway just behind the nose. When we breathe through our nose, air passes through the nasal cavity en route to the pharynx and tracheobronchial tree, which leads into the lungs. The paranasal sinuses are air-filled cavities around the nose.

Nasopharyngeal Cancer
The nasopharynx is the upper part of the throat behind the nose - the nostrils lead into it, and openings on the sides of the nasopharynx connect to the ears.

Cancers of the Oral Cavity
The oral cavity includes all the various parts of the mouth: the lips; the lining inside the lips and cheeks (the buccal mucosa); the bottom of the mouth; the front of the tongue; the front part of the top of the mouth (the hard palate); the gums; and the area behind the wisdom teeth (the retromolar trigone).

Tumors of the Oropharynx
The oropharnyx is the part of the throat at the back of the mouth (the throat is technically known as the pharynx). It's a 5 inch, hollow tube that extends all the way from the nose down to the top of the trachea (the windpipe that leads to the lungs). Parts of the oropharnyx include the back of the tongue, the soft palate (the back part of the roof of the mouth), the tonsils and the part of the throat behind the mouth.

Hypopharyngeal Tumors
The hypopharynx is the bottom part of the pharynx, or throat. The pharynx is a 5-inch hollow tube that extends from the nose, down the neck to the esophagus. Both air and food pass through the pharynx. The air continues on through the trachea to the bronchi and lungs. Food continues on to the esophagus and digestive system.

Laryngeal Cancer
The larynx is more commonly known as the "voicebox." It's a 2 inch, tube-shaped organ in the neck. Air passes through the larynx on its way into or out of the lungs, and when we talk the vocal cords inside of the larynx tighten up and vibrate, producing sound.

Salivary Gland Cancer
Salivary glands are located throughout the oral cavity. They are responsible for making saliva, a substance that keeps the mouth moist and aids in digestion.

Treatment and Clinical Trials
Head and neck cancer is often complex, with many different sites and staging systems. However, current therapy offers several alternatives, including surgery, radiation, and chemotherapy, either alone or in combination.