What Causes Laryngeal and Hypopharyngeal Cancers?

In general, cancer begins when a genetic mutation (change in certain genes) turns normal, healthy cells into abnormal cells. Healthy cells grow and multiply at a set rate and eventually die at a set time. Abnormal cells grow and multiply out of control, and they do not die. Instead, the abnormal cells clump together to create a mass (tumor). Cancer cells invade nearby tissues and can separate from an initial tumor to spread to other parts of the body (metastasize).

Certain substances, especially certain chemicals in tobacco, damage the DNA in the cells that line the larynx and hypopharynx. DNA contains genes that tell cells how to carry out their jobs. When DNA is damaged, it can no longer stop laryngeal or hypopharyngeal cells from growing too much. As a result, abnormal cells begin to grow more quickly and form tumors. About 85 percent of all cases of head and neck cancer are associated with tobacco use.

Alcohol also damages DNA, perhaps by increasing the ability of chemicals (such as tobacco) that damage DNA to invade cells. For this reason, the combination of alcohol and tobacco causes more damage to DNA than tobacco or alcohol alone.

Risk Factors for Laryngeal and Hypopharyngeal Cancers

Doctors and researchers believe that certain factors, known as risk factors, increase a person’s chances of getting laryngeal and hypopharyngeal cancers. However, not everyone with a risk factor will develop these kinds of cancer and people without any risk factors can develop these diseases.

Risk factors for laryngeal and hypopharyngeal cancers include:

• Age - The risk of laryngeal and hypopharyngeal cancers increases with age. More than half of all cases are diagnosed in people over 65.
• Alcohol - People who drink a lot of alcohol are much more likely to develop laryngeal and hypopharyngeal cancers than people who do not drink. The risk increases with the amount of alcohol consumed. The combination of alcohol and tobacco is particularly dangerous because people who use both substances are up to 100 times more likely to develop these diseases than those who do not smoke or drink alcohol.
• Diet - A diet low in fruits and vegetables (and possibly in vitamin A, which is found in carrots, sweet potatoes, and other colored vegetables) can increase your risk of cancer of the larynx and hypopharynx.
• Gastrointestinal reflux disease (GERD or heartburn) - In GERD, acid from the stomach backs up into the esophagus (a tube that goes from the throat to the stomach). This causes a burning sensation and can damage the esophagus and hypopharynx. GERD may be a risk factor for cancers of the larynx and hypopharynx.
• Gender - Men are four or five times as likely as women to develop laryngeal and hypopharyngeal cancers. This might be because men tend to use tobacco and alcohol more often than women. However, as more women use tobacco and drink alcohol, the difference in rates of laryngeal and hypopharyngeal cancers between men and women is decreasing.
• Human papillomavirus (HPV) infection - HPV is a sexually transmitted disease that invades certain skin cells. A few of the more than 100 HPV types cause most cancers of the cervix and may play a role in some cases of laryngeal and hypopharyngeal cancer.
• Occupational exposure - People who are exposed over long periods of time to wood dust, paint fumes, and certain industrial chemicals (including nickel and asbestos) have an increased risk of laryngeal and hypopharyngeal cancers.
• Personal history - If you have had a head and neck cancer in the past, you have a higher risk of developing another cancer in the head or neck, especially if you smoke.
• Plummer-Vinson syndrome (Paterson-Kelly syndrome, sideropenic dysphagia) - People with Plummer-Vinson syndrome have too little iron in their blood. They also have trouble swallowing because weblike growths of tissue block their esophagus. This very rare condition increases the risk of hypopharyngeal cancer.
• Race - Laryngeal and hypopharyngeal cancers are about 50 percent more common in African-Americans than in white people.
• Tobacco - Smokers are much more likely than nonsmokers to develop laryngeal and hypopharyngeal cancers. The risk of laryngeal and hypopharyngeal cancers increases with the amount smoked or chewed and the number of years of tobacco use. If you stop smoking, your risk of these diseases will decrease.
• Weakened immune system - If you have a weak immune system (your immune system protects you from infections) due to a disease or medicine, you might have a higher risk  of laryngeal and hypopharyngeal cancers.

This content has been reviewed and approved by Myo Thant, MD.