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Understand head and neck cancer

About 4% of all cancers in the US each year are diagnosed as head and neck cancer, and more men will be diagnosed than women.

The information on this page may help you gain a better understanding of your head and neck cancer diagnosis and what’s happening to your body. This may help when making important decisions with your doctor.

From Harvard Health Publishing

What is head and neck cancer?

A Doctor Explaining What Head and Neck Cancer Is to a Patient

When cancer cells or tumors are found in the mouth, throat, voice box, paranasal sinuses and nasal cavity, or salivary glands, it’s called head and neck cancer. In 2021, it was estimated that more than 68,000 men and women in the United States would be diagnosed with head and neck cancer, which again, includes cancers of the mouth (also called the oral cavity); throat (pharynx); voice box (larynx); nasal cavity and paranasal sinuses (small hollow spaces in the bones surrounding the nose); and salivary glands.

Most head and neck cancer occurs in the mouth, throat, or voice box.

When detected early, head and neck cancers are generally considered to be highly treatable and curable. A little background knowledge can go a long way in terms of helping patients obtain an early diagnosis, which offers the best chance for successful treatment.

Where head and neck cancer develops

To better understand how the various types of head and neck cancer form, it’s helpful to know a little about the anatomy of each area.


You use it to talk, taste, chew, laugh, kiss, and more, but have you ever taken the time to think about the many parts that make up your mouth? Also called the oral cavity, the mouth consists of the lips, gums, top and bottom of mouth (including under the tongue), front two-thirds of the tongue, and lining of the cheeks and lips. It also includes the gum areas behind the wisdom teeth. Cancer can develop in any of these areas.


The throat, also called the pharynx (pronounced “fare-inks”), is a 5-inch-long tube that starts behind the nose and travels down the neck. It makes sure that the food and water you eat and drink make their way toward the stomach and the air you breathe goes towards the lungs.

If your cancer is located in your throat, your doctor may refer to it as throat cancer, or he or she may be more specific and call it:

  • Nasopharyngeal cancer if it is in the upper part of the throat, behind the nose. This area of the throat is called the nasopharynx.
  • Oropharyngeal cancer if it is in the middle of the throat, which includes the base of the tongue, the tonsils, or the back of the mouth. This area of the throat is called the oropharynx.
  • Hypopharyngeal cancer if it is in the lower part of the throat, which is called the hypopharynx.

Voice box

When you talk, sing, laugh, grunt, or make any sort of noise, you’re using your voice box, which is also known as the larynx (pronounced “lair-inks”). This important area of the head and neck is a small passageway for air to move between the lungs and the throat. It contains the vocal cords, Adam’s apple, and a small flap of tissue called the epiglottis. Like the throat, the voice box is divided into three sections:

  • Supraglottis: the upper part of the voice box, located above the vocal cords.
  • Glottis: the middle part of the voice box, where the vocal cords are located.
  • Subglottis: the lower part of the voice box.

Paranasal sinuses and nasal cavity

Several bones are located around the nose. Small spaces inside those bones are filled with air and are called the paranasal sinuses. There are four pairs of paranasal sinuses:

  • Maxillary sinuses: in the cheeks, on both sides of the nose below the eyes.
  • Frontal sinuses: above the eyes and eyebrows.
  • Ethmoidal sinuses: above the nose, between the eyes.
  • Sphenoid sinuses: between the eyes, but deep behind the nose.

The nasal cavity is the space inside the nose itself and extends along the top of the roof of the mouth before curving downward where it meets the upper throat.

Salivary gland

You have both major salivary glands and minor salivary glands. There are three pairs of major salivary glands:

  • Parotid glands: the largest of all the salivary glands, located just below and in front of both ears.
  • Sublingual glands: which sit under the tongue, in the bottom of the mouth.
  • Submandibular glands: located beneath the jawbone.

In addition, hundreds of invisible minor salivary glands are sprinkled throughout the mouth, mainly in the tongue; the lining of the lips; the top of the mouth; the inside the cheeks, nose, sinuses; and the voice box.

Why do some cells turn cancerous?

While often the exact trigger cannot be identified, certain factors may make it more likely that cancer develops, including lifestyle choices (tobacco use, alcohol use, exposure to toxic substances); genetics (a tendency to develop cancer that you inherit from your family); and some viruses.

See more questions to ask your doctor

Types of head and neck cancer

There are many different types of head and neck cancer, with cancer cells or tumors occurring in the mouth, throat, voice box, paranasal sinuses and nasal cavity, or salivary glands.

Squamous cell carcinoma

A layer of flat, thin cells, called squamous cells, lines the moist outermost tissue inside the head and neck. If you were to look at them under a microscope, they would look like fish scales. Most head and neck cancer – about 90 percent – starts in these cells. When this happens, it is called head and neck squamous cell carcinoma (HNSCC), or simply squamous cell carcinoma.

If the phrase sounds a bit familiar, it’s likely because you have heard of squamous cell carcinoma of the skin, the second most common type of skin cancer. Squamous cells are found in the skin’s surface, too.


A smaller percent of head and neck cancer is called adenocarcinoma. Unlike squamous cell carcinoma, adenocarcinoma forms in a different type of tissue that lines parts of the head and neck. This tissue is called glandular tissue, and it makes mucus and other fluids. Head and neck adenocarcinoma usually affects the paranasal sinuses or salivary glands, not the mouth, throat, or voice box.

Learn About Biomarker Testing

Head and neck cancer staging: What is it and how does it work?

A Doctor Explaining the 5 Stages of Head and Neck Cancer

Staging is a way to describe a cancer. The cancer’s stage tells you where a cancer is located, its size, if it’s grown into nearby tissues, and if it’s spread to nearby lymph nodes or other parts of the body. Staging is a critical step in any patient’s cancer journey and is used to help decide what treatments will be used to fight your cancer. So, before you and your doctor create your treatment plan, you’ll need to have your cancer staged.

The five stages of head and neck cancer

Staging of head and neck cancer varies depending on the location of the primary cancer site. There are five stages of cancer, Stage 0 through Stage 4. In general, the higher the number, the more the cancer has spread.

Head and neck cancer can arise in a number of different sites, and the staging criteria vary slightly depending on where the cancer started. Staging also helps the doctor determine your prognosis, which describes the chances that your cancer may or may not return.

Stage 0

A stage 0 rating means cancer cells have been found in the lining of the affected area (the mouth or throat, for instance), but have not grown into deeper tissues. Stage 0 cancer is also called carcinoma in situ. In situ is Latin for “in position,” a reference to the fact that the cancer cells appear to be contained.

Stage 1

Most stage 1 cancers are 2 centimeters or smaller (one centimeter is about as wide as an average pencil) and have not spread to the lymph nodes or any other part of the body.

Stage 2

Most stage 2 cancers are larger than 2 centimeters but smaller than 4 centimeters and have not spread to the lymph nodes or any other part of the body.

Stage 3

A stage 3 cancer usually is one of two things: 

  • a tumor larger than 4 centimeters or 
  • has spread to a lymph node on the same side of the neck as the tumor, and that lymph node is smaller than 3 centimeters.

Stage 4

The most advanced stage of head and neck cancer, stage 4 cancer may be any size and have spread. There are multiple ways it may have spread. These include:

  • spread to other areas of the head and neck
  • spread to a lymph node larger than 3 centimeters on the same side of the neck as the tumor
  • spread to multiple lymph nodes of any size on the same side of the neck as the tumor
  • spread to a single lymph node of any size on the opposite side of the neck as the tumor
  • spread to a distant part of the body, such as the lungs or liver

Learn about a possible treatment option for certain patients with head and neck cancer.

The many languages of staging

Staging can be confusing and, in some ways, is a language all its own. For instance, the staging system described above is determined by the TNM staging method.

TNM stands for Tumor, Node, Metastasis and uses letters and numbers to describe the size and depth of the tumor (T); whether it has spread to lymph nodes (N); and whether it has spread to a different part of the body besides the lymph nodes (M). You may hear these numbers and letters used to describe your cancer.

For instance, mouth (oral cavity) cancer that has spread to the bones or skin of the jaw or face, deep muscle of the tongue, or sinus cavity; has spread to one lymph node on the same side but that lymph node is no bigger than 3 centimeters; and has not spread to any distant organs or sites is described as Stage 4A (T4a N1 M0).

This staging method can be hard to understand, so be sure to discuss more with your doctor.

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