Head and Neck Cancer
What are head and neck cancers?
Head and neck cancer is a term used to describe the cancers that start in the tissue or lymph nodes in the head and neck area, which includes the mouth, tongue, palate, gums, salivary glands, tonsils, throat (pharynx), voice box (larynx), nose and sinuses. Most head and neck cancers start in the cells that line the moist surfaces of the mouth, nose or throat (also known as squamous cells). These cancers are therefore referred to as squamous cell carcinomas (SCC).
Locally advanced head and neck cancer is a type of head and neck cancer that has spread from where it started to nearby tissue or lymph nodes, while recurrent head and neck cancer is a type of head and neck cancer that has come back, usually after a period of time during which the cancer could not be detected.
Metastatic head and neck cancer occurs when the cancer cells within the tumour have spread from the original location to other parts of the body. When head and neck cancer spreads (or metastasises), it can spread to the lungs, or other parts of the body.
Types of head and neck cancers
Cancers of the head and neck are usually identified by the area of the head or neck where they begin.
These include:
Mouth ( oral cavity)
Cancer can begin in any part of the mouth. The areas that may be affected include the lips, the front two-thirds of the tongue, the gums, the lining inside the cheeks and lips, the floor (bottom) of the mouth under the tongue, the hard palate (bony top of the mouth), and the small area behind the wisdom teeth. Cancer which starts in the mouth is called oral cancer.
Nasal cavity and paranasal sinuses
The nasal cavity is a large, hollow space inside the nose which helps to filter, moisten and warm the air we breathe. The bones around the nasal cavity have a group of small, air-filled spaces called the paranasal sinuses.
There are four pairs of paranasal sinuses. These include:
- ethmoid sinuses located above the nose and between the eyes
- frontal sinuses located behind the forehead
- maxillary sinuses located under the eyes and in the cheek area
- sphenoid sinuses located behind the nose and between the eyes
Cancerous cells can also develop in the tissues of the paranasal sinuses and nasal cavity.
Salivary glands
The salivary glands produce saliva which keeps the mouth moist, helps with swallowing of food and protection of the mouth against infections. The major salivary glands include:
- parotid glands, which are in front of the ears
- sublingual glands, which are under the tongue
- submandibular glands, which are under the jawbone
Most salivary gland cancers affect the parotid glands. In some instances, cancers in the salivary gland may also affect the submandibular and sublingual glands.
Throat (pharynx)
The throat, also called pharynx, is a hollow tube that starts behind the nose and leads to the food pipe (oesophagus), and the windpipe (trachea). The pharynx has 3 parts, which include:
- Nasopharynx: This is the upper part of the pharynx, behind the nose and above the soft palate. Cancers that develop
in this area are called nasopharyngeal cancers. - Oropharynx: This is the middle part of the pharynx, the area from the soft palate and base of the tongue to the back
of the mouth, including the tonsils. Cancers that develop in this area are called oropharyngeal cancers. - Hypopharynx: This is the lower part of the pharynx, around the voice box (larynx). Cancers that develop in this area
are called hypopharyngeal cancers.
Larynx
The larynx or voice box is a short passageway formed by cartilage, just below the pharynx in the neck. It connects the lower part of the throat (hypopharynx) with the windpipe (trachea). The larynx contains the vocal cords. It also has a small piece of tissue, the epiglottis, which covers the larynx, preventing food from entering the air passages.
Cancer that affects the larynx is called laryngeal cancer.
