About head and neck cancers

Head and neck cancer is a general term for a range of cancers that start in the head and neck region.

Learn more about:

• What is head and neck cancer?
• The head and neck
• Other cancers in the head and neck area
• Types of head and neck cancers

What is head and neck cancer?

About 9 out of 10 head and neck cancers start in the moist lining of the mouth, nose or throat. The lining is called the squamous epithelium, and these cancers are called mucosal squamous cell carcinomas (SCCs). Some head and neck cancers start in glandular cells, and many of these cancers are called adenocarcinomas. SCCs and adenocarcinomas can also occur in other parts of the body.

Recently, skin cancers (cutaneous carcinoma) that start in the head and neck area have been classified as a type of head and neck cancer. To learn more about these, see Skin cancer.

The head and neck

In cancer medicine, the term “head and neck” has a particular meaning. The head and neck region includes the:

• mouth – made up of the lips and the structures inside the oral cavity such as the tongue, palate and gums
• throat – known as the pharynx
• voice box – known as the larynx
• nose – made up of the nasal cavity (the area behind the nose) and the sinuses
• salivary glands – in the floor of the mouth and near the lower jaw
• skin of the head and neck.

Other structures found in our head and neck are not considered part of the “head and neck” in cancer medicine (although they can be affected by nearby head and neck cancers and their treatment, and can also have their own types of cancer). These include the:

• brain
• eyes
• thyroid – a hormone-producing gland found at the front of the neck and just below the voice box
• oesophagus – the food pipe
• trachea – the windpipe
• bones and muscles of the head and neck.

Lymph nodes in the head and neck – The head and neck region also contains many lymph nodes. Lymph nodes are small, bean-shaped structures found throughout the body. They form part of the lymphatic system, which helps protect the body against disease and infection. When cancer spreads, it usually spreads to nearby lymph nodes first.

Anatomy of the head and neck

This diagram gives an overview of the main areas of the head and neck.

Lymph nodes in the head and neck

Types of head and neck cancers

Cancers of the head and neck are categorised by the area of the head or neck where they begin.

Mouth (lip and oral cavity) cancers

Cancer that starts in the mouth is known as oral cancer. The mouth is made up of the lips and the oral cavity. The oral cavity includes the:

• gums
• lining of the cheeks and lips
• front two-thirds of the tongue (oral or mobile tongue)
• floor of the mouth under the tongue
• bony roof of the mouth (hard palate)
• small area behind the wisdom teeth (retromolar trigone).

The area at the back of the mouth is called the oropharynx. It includes the base of the tongue, the tonsils, the uvula and the soft palate, as well as the middle section of the throat. Cancer of the oropharynx is known as oropharyngeal cancer.

Oral cavity

Throat (pharyngeal) cancers

The throat, also called the pharynx, is a hollow tube that starts behind the nose and leads to the food pipe (oesophagus) and the windpipe (trachea).

The pharynx has three main parts:

• nasopharynx – the upper part behind the nose and above the soft palate; cancer starting in this area is called nasopharyngeal cancer
• oropharynx – the middle part, the area from the soft palate and base of the tongue to the back of the mouth, including the tonsils; cancer starting in this area is called oropharyngeal cancer
• hypopharynx – the lower part, around the voice box (larynx); cancer starting in this area is called hypopharyngeal cancer. Cancers in the three parts of the pharynx are treated differently.

Pharynx

Voice box (laryngeal) cancers

The voice box, also called the larynx, is the entry point to the windpipe (trachea). It contains the vocal cords and protects the lungs. Cancer that starts in the larynx is called laryngeal cancer.

The larynx has three main parts:

• supraglottis – the area above the vocal cords; includes the epiglottis, a small flap of tissue that covers the larynx when you swallow and prevents food and fluids going into the trachea and lungs
• glottis – the area containing the vocal cords, which vibrate when air passes through them to produce the sound of your voice
• subglottis – the area below the vocal cords leading to the trachea.

The thyroid gland is in front of the trachea under the voice box, but thyroid cancer is not considered head and neck cancer.

Larynx

Nose (nasal cavity and sinus) cancers

The nasal cavity is the large, hollow space behind the nose. It is separated into two main cavities by the nasal septum, a thin wall of bone and cartilage in the centre of the nose.

The paranasal sinuses are small, air-filled spaces in the side walls of the nose. They help to warm and moisten air passing to the lungs. They also influence the sound and tone of your voice.

There are four pairs of paranasal sinuses:

• maxillary sinuses – under the eyes and in the cheek area
• frontal sinuses – behind the forehead
• ethmoid sinuses – above the nose and between the eyes
• sphenoid sinuses – behind the nose and between the eyes.

Cancer that starts in the upper part of the throat behind the nose is called nasopharyngeal cancer.

Nasal cavity and sinuses

Salivary gland cancers

The salivary glands make the watery substance known as saliva. This keeps the mouth moist to help with swallowing and talking and also protects the mouth and teeth.

There are three pairs of major salivary glands:

• parotid glands – in front of the ears
• submandibular glands – under the lower jaw
• sublingual glands – under the tongue.

There are also hundreds of smaller glands throughout the lining of the mouth, nose and throat. These are known as the minor salivary glands.

Cancers can start in the major or minor salivary glands. When cancer is found in one of the parotid glands, it has often spread from a skin cancer on the head or neck.

Salivary gland