The throat is found at the back of the mouth, which includes the area behind the nose and extends to the top of the larynx (also called voice box, windpipe) and esophagus (also called food pipe). Also found here are the tonsils, the tissue flap that covers the larynx, called the epiglottis, the back portion of the tongue, the posterior soft palate (the roof part of the mouth) and the back part of the throat.
Throat cancer develops when there is an abnormal cell growth involving any of the tissues in the throat. This abnormal growth and multiplication of cells may destroy the surrounding normal cells and can affect other parts of the body.
There are different areas in the throat that may be affected by cancer, and these are classified accordingly.
- Cancer of the nasopharynx involves the uppermost portion of the throat behind the nose
- Cancer of the oropharynx involves the middle throat area, including the tonsils and base of one’s tongue
- Cancer of the hypopharynx involves the lower throat area
- Cancer of the larynx involves the windpipe or voice box, including vocal cords
Cancer of the throat has been diagnosed in about 25,000 Americans in 2010, and there were around 6,000 deaths attributed to it in the same year. Statistics show that cancer of the larynx is one of the most common cancers involving the head and neck. Each year, it is estimated that about 2,400 adults (1,900 men: 500 women) in the US will be diagnosed with hypopharyngeal cancer.
Causes and Risk Factors
Genetic mutations involving the cells in the throat lead to abnormal growth of cells, causing damage to normal tissues. This abnormal proliferation of cells forms a tumor (cancer), which may invade other nearby or distant tissues. The exact cause of these genetic mutations is yet unknown. However, there are risk factors that may lead to the development of throat cancer, including:
- Using tobacco, either smoking or chewing it
- Excessive intake of alcohol
- Poor oral hygiene
- Infection with human papillomavirus (HPV)
- A diet lacking fruits and vegetables
- Asbestos exposure and exposure to other pollutants and chemicals
- Advancing age (more than 60 years usually)
Studies show that about 75% of throat cancers are associated with smoking and alcohol abuse. Your risk for developing throat cancer is greater when both of these risk factors are combined.
Signs and Symptoms
During the early stage of throat cancer, symptoms may resemble those of a throat infection. You may experience cough, hoarseness, sore throat, and changes in your voice if the larynx is affected. If the tonsils or areas at the back of the mouth are affected, one may feel a lump in the throat, difficulties in swallowing, or pain. What distinguishes these symptoms from an infection or trauma is that the symptoms usually last longer than expected and do not respond to treatment with antibiotics or pain medications. The symptoms may persist for more than 2 to 4 weeks and become progressively worse.
During later stages, symptoms may overlap since the respiratory and digestive parts of the throat are near each other. You may therefore experience difficulties in swallowing, eating, breathing, and talking. There may be difficulties chewing, jaw pain, and a persistent lump. You may also feel that food may be stuck in the throat or chest, which may be accompanied by hiccupping. Pain and swelling may be felt in the ear, eye, nose, jaw, and neck. Discolorations or patches may be seen inside the mouth or throat, but these may later become bigger and more distinctively a tumor. In the later stages, you may notice unexplained, progressive weight loss.
Although these symptoms may initially resemble those of a respiratory infection or traumatic injury in the throat, you must consult a physician if the symptoms last longer than 2-4 weeks, they are progressively worsening, and they are not relieved by antibiotic treatment or pain medications.
Throat Cancer Diagnosis
Throat cancer may be diagnosed by performing a laryngoscopic examination followed by endoscopy and tissue biopsy. These are usually done under anesthesia in an outpatient setting. During the procedure, the doctor inserts a flexible tool with a small camera. Small lumps of tissue may be obtained for laboratory examination in order to confirm the diagnosis.
Throat Cancer Treatment
Treatment of throat cancer depends on factors including stage of the disease, types of cells involved, location of the cancer, the general health status of the patient, and patient preferences.
Radiation therapy or radiotherapy is the treatment of choice when the tumor is small and cancer has not spread to other areas. It involves delivering high-energy particles in beams, which focus on the cancerous tissue. These particles kill cancer cells or stop the abnormal cells from multiplying.
For the early stage of throat cancer, radiation therapy alone may be necessary for treatment. In advanced cases, this form of therapy may be combined with surgery or chemotherapy. This may be performed to shrink a large tumor before doing surgery, increasing the chance of success.
In very advanced cancers, radiotherapy can reduce the signs and symptoms by trimming down the size of the tumor, making the patient more comfortable. It can also be used after surgery to kill remaining cancer cells.
Different surgical techniques may be performed to remove a tumor or part of a large tumor. Surgery may treat cancer, prevent its spread, or alleviate symptoms. The type of surgery performed will depend on the size of the tumor, the location of the tumor, and whether the tumor has spread to other nearby tissues or lymph glands.
Endoscopic resection. This technique is used to remove a small tumor in the throat. Instruments are inserted through a hollow tube that is passed down the throat to cut out a tumor. A laser may be used to vaporize the tumor. This is a noninvasive technique that does not involve cutting from the outside.
Partial laryngectomy. This operation involves removing the affected part of the larynx. An incision is made in the front of the neck to access the larynx. Since only part of the larynx is removed, you will not need a 'hole in the neck' or stoma to breath, and the ability to speak can be retained. However, a temporary hole or stoma may be necessary while the wound is healing.
Total laryngectomy. This operation involves removal of the entire larynx. Breathing is accomplished through a permanent hole (stoma) made in the front of the neck. It involves removal of the vocal cords so the ability to speak normally is lost. However, a speech therapist can help teach the patient techniques to enable him to speak in another way.
Total or partial pharyngectomy. Smaller tumors may require surgical removal of only part of the throat. Reconstruction may be performed to facilitate the normal swallowing of food. Removal of the entire throat includes removal of the larynx as well.
Neck dissection. If the cancer has spread to the lymph nodes, surgical removal of some or all of the involved lymph nodes may be performed by dissecting the neck.
The use of anti-cancer drugs to kill cancer cells and prevent their spread is called chemotherapy. It may be done in combination with surgery and/or radiation. Some drugs can make cancer cells more sensitive to radiation. However, combining these drugs with radiation therapy can also increase side effects.
Targeted Drug Therapy
Drugs used to bind to specific receptors found in the cancer cells can treat cancer. Cetuximab (Erbitux) is one type of drug that has been approved for the treatment of throat cancer. It works by locking onto the receptors, thereby preventing the cancer cells from growing and multiplying. It may be used in combination with radiation therapy.
Post Treatment Rehabilitation
The different modes of treatment for throat cancer may bring complications that require rehabilitation to regain the ability to speak, swallow, and eat. Post-treatment rehabilitation may require specialists to care for a neck opening (stoma), to relieve difficulties in eating, swallowing, and speech, as well as to treat stiffness and pain in the neck.