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Types of Cancer > Head and Neck Cancers > Oropharyngeal Cancers > Overview

Head and Neck Cancers: The Basics

Carolyn Vachani, RN, MSN, AOCN
Affiliation: Abramson Cancer Center of the University of Pennsylvania
Last Modified: March 5, 2008

What is the "head and neck"?

This may seem like a silly question to address, but it is important when talking about head and neck cancers that you understand exactly which areas the cancer includes. The pharynx is a tube about 5 inches long, extending from the back of the nose to the area where the esophagus (tube to the stomach) and the trachea (tube to the lungs) both begin. In terms of head and neck cancers, the pharynx and the surrounding structures are divided into several areas:

• Oral cavity: includes the lips, front part of the tongue, roof of the mouth (hard palate), floor of the mouth, parts of the gum line (alveolar ridge), and the inside lining of the cheeks (buccal mucosa)
• Nasopharynx: includes the nasopharynx (area of the pharynx behind the nose) and the lining of the nose
• Oropharynx: includes the posterior pharynx wall (area of the pharynx behind the mouth), the soft part of the roof of the mouth (soft palate), tonsils, and the base of the tongue
• Hypopharynx: includes the area of the pharynx below the oropharynx down to the esophagus
• Larynx: includes the voice box (larynx), which is located just below the pharynx, and the epiglottis, which is a flap of tissue that prevents saliva and food from entering the trachea when one swallows
• Sinuses (frontal, ethmoid, maxillary, sphenoid) and salivary glands (major and minor glands)
• Parts of the ear (external auditory canal, middle and inner ear)
• Neck (lymph nodes, etc.)

This graphic is looking at a head that is cut down the center.

1. sinuses,
2. lining of the nose,
3. nasopharynx,
4. tongue,
5. oropharynx,
6. hypopharynx,
7. larynx,
8. spinal cord,
9. vertebrae,
10. esophagus,
11. Trachea

What are head and neck cancers?

In the United States, there will be an estimated 47,500 new cases of head and neck cancer (HNCA) in 2008, with 11,200 people dying from the disease. Globally, there are an estimated 533,100 new cases a year, and it is the fifth most common cancer worldwide. In contrast, HNCA does not rank in the top 10 in the US, accounting for only 3% of all cancers. The variations in rates around the world are a result of differences in dietary and tobacco habits, alcohol use, and viral and environmental exposures.

You can see that this category encompasses quite a few different cancers. All cancers begin when abnormal cells in a part of the body begin to grow in an out-of-control manner. That is about where the similarities end, as different cancer types are treated in different ways, and head and neck cancers are no exception. This is an introductory article, so you may need to use the links on the left to get more detailed information on specific types of head and neck cancer.

What are the causes of head and neck cancer, and am I at risk?

It is estimated that 80-90% of all head and neck are caused by tobacco and alcohol use. Tobacco includes cigarettes, cigars, pipes, and smokeless tobacco (chew, dip, snuff, and betel quid). Tobacco users are between 20-40 times more likely to develop head and neck cancer than non-smokers, depending on the amount of use, as well as the age, sex and race of the user. Smoking more than 4 cigarettes a day increases the risk to 20 times that of a non-smoker. The composition of smokeless tobacco varies around the world, making it hard to generalize, but the risk of developing head and neck cancer is thought to be 1-10 times more for smokeless users than non-users. Quitting smoking leads to a reduction of risk that increases with time, but will never reach that of a never-smoker.

Drinking alcohol is known to increase the risk of developing head and neck cancer about 2-10 times that of non-drinkers, depending on the amount consumed. Alcohol use alone increases risk, but when combined with tobacco, the risk increases dramatically. Some researchers believe alcohol may make the tissues more susceptible to damage from the toxins in tobacco.

Men develop head and neck cancer twice as often as women in the United States, and make up 68% of all cases and 71% of the deaths from this disease. For example, in cancer of the tongue specifically, roughly 1,200 men will be diagnosed this year, versus only about 670 women. As people age, their risk increases, and most cases are diagnosed in people over age 65. African-American and Asian individuals are at higher risk for all types of head and neck cancers. Although oral and pharyngeal cancers have decreased over the last 20 years among white males and females under age 65 and in black women of all ages, it has increased in black males.

Infection with certain strains of the Human Papilloma Virus (HPV), a sexually transmitted disease that invades human epithelial tissue (a type of skin cell), is known to increase risk of oropharyngeal cancers. It is estimated that 5.5 million people worldwide are infected with this virus annually. Sexually active individuals have an 80 to 85% chance of being infected at some time in their life. Researchers estimate that 50% of oropharyngeal cancers are attributable to HPV, with a much higher rate in young non-smokers diagnosed with the disease. This is thought to be related to changes in sexual practices, including an increase in oral sex among adolescents and young adults. Despite the decrease in smoking-related cancers in the U.S., this HPV-related increase has the potential to become a serious public health burden.

Rates of nasopharyngeal cancers in Asian countries are high and thought to be a result of a diet high in salt-cured foods. Chronic sun exposure is linked to cancer of the lip. Exposure to asbestos is thought to increase the risk of laryngeal cancers. Inactive infection with the Epstein Barr virus (EBV), environmental or second-hand smoke, and the chronic inhalation of wood dust have all also been associated with increased risk of head and neck cancers.