Cancer of the Throat and Larynx

Introduction

Cancer in the throat occurs in the passages from the neck to the rest of the body. This includes the voice box, or larynx, and the areas behind the oral cavity, known as the pharynx.

What is going on in the body?

The throat is exposed to every substance a person takes into the body whether by breathing, drinking, or eating. Some of these substances, especially tobacco, can cause severe damage to the cells lining the throat. Damage over time may cause cells to undergo changes that lead to cancer. The person may have more than one cancer develop at a time in this area because the damage affects the whole area.
After a cell becomes cancerous, it will begin to grow and divide uncontrollably. The cancer cells will then form a tumor. The tumor spreads by invading the tissue around it. Some of the cancer cells will enter the system that drains fluids into lymph nodes in the neck. The lymph nodes filter the blood and help fight infections. When a cancer cell enters a lymph node, it may also be filtered out, and form a new tumor in the node.
Cancerous cells from the tumor can also break off from the tumor and enter the blood stream. These cells will go to other parts of the body and develop into new tumors. The cancer will spread, or metastasize, through the body if not successfully treated. The cancer causes death from damage to vital organs.

What are the causes and risks of the disease?

People who use tobacco products and also drink beverages containing alcohol are at great risk for developing these cancers as well as cancers in the mouth. Alcohol consumption tends to accelerate the damage caused by tobacco.   

What are the signs and symptoms of the disease?

Symptoms depend on where the cancer is located. Cancers at the base of the tongue will cause throat pain and difficulty swallowing. Cancers on the voice box or larynx will cause hoarseness by pressing on the vocal cords.

How is the disease diagnosed?

When a tumor is found, a small piece of it must be removed with a biopsy, to determine if it is cancerous. Surgery is usually performed to remove the rest of the tumor, known as resection, and to determine the extent of the disease. It is likely that a large tumor might have spread to local lymph nodes by the time of diagnosis. Nearby lymph nodes will be removed at the time of surgery to determine this. Other tests such as CT scans of the chest and neck may be performed to investigate potential spread to distant sites. Understanding the extent of the disease will guide the choices of therapy

What are the treatments for the disease?

Surgery to remove the tumor and tissue around it is the primary treatment. If it is suspected that lymph nodes are involved, then nearby lymph nodes in the neck will be removed. Radiation therapy may be applied to the area of surgery later to improve the likelihood that all of the cancer has been destroyed. Sometimes a very small tumor is found on the vocal cords. At that stage it has not spread. In this rare instance, surgery may be avoided by directing radiation at the tumor. Treatment for this type of cancer that has spread to other parts of the body is directed at improving quality of life. It is not curable in the advanced stages. Chemotherapy may be given to reduce the size of the tumors. Radiation may be given to areas of local pain.

What are the side effects of the treatments?

Extensive surgery on the throat will have long-term consequences. If the larynx has to be removed, the person will be unable to talk and will have a tracheostomy, or permanent breathing tube in the neck. A special device can be placed that will aid speech, but it will not be normal speech. Surgery on the neck will also change the contour of the neck. Reconstruction at the time of surgery may improve this.
The effects of radiation are temporary and resolve after treatment. The more troublesome side effects include dry mouth, sores developing in the mouth and throat, and fatigue.
Sometimes chemotherapy is given during radiation to make the radiation work better. In this case, the effects of the radiation may be stronger. When given to control advanced disease, the medications are chosen to improve quality of life. Most side effects such as nausea can be easily managed.

What happens after treatment for the disease?

After treatment of early stage disease, the person will need to be followed closely. It is possible new cancers may form or that the previously treated cancer can recur. In advanced stage disease, the person will be followed to determine response. The disease is likely to progress over time.  


Reference 
 Ridge, J.A.; Hooks, M.A.; Lee, W. R.; & Benner, S.A. (1996). Head and neck cancers in Cancer Management: A Multidisciplinary Approach. PRR: Huntington, NY. Pp. 432-465.