What is Head and Neck Cancer?
What is cancer?
Our bodies are made up of millions of cells. Each cell has a specific job. Groups of cells with the same job make up tissues and organs, for example, skin or muscles.
Cells multiply to help our bodies grow and repair. When cells multiply in an abnormal way, they can form a lump (also known as a tumour), and damage the normal cells close by.
Not all lumps are cancer. Lumps or tumours that are not cancer are called benign. When a lump is a cancer, it is called malignant. That means the cancer cells take over the area of the body they are growing in.
Cancer can spread from one place to other parts of the body. Cancer spreads when cells travel through the lymphatic system to the lymph nodes or when cells break off the main lump and get carried in the blood to other parts of the body, where they can start growing. This is called metastasis.
What is Head and Neck Cancer?
Head and Neck Cancer includes a range of different cancers that are classified based on their location in the head or neck and the type of cancer cells.
Head and Neck Cancer often refers specifically to cancers that begin in the cells that line the moist mucosal surfaces including the mouth (oral cavity), nose and sinuses, throat (pharynx) and voice box (larynx).
- These cancers are usually squamous cell carcinomas (SCCs) and account for about 95% of cases.
- Mucosal Head and Neck Cancers are diagnosed in approximately 3,500 Australians every year; representing 2–3% of all cancers.
- Mucosal Head and Neck Cancer is nearly twice as common in men and often diagnosed in people over the age of 50.
Thyroid Cancers are more common that mucosal Head and Neck Cancers and occur in 2,400 Australians every year. They are more common in women and often occur at a younger age.
Skin Cancers of the head and neck are so common in Australia that we don’t even know how many occur. It is estimated that more than 500,000 Australians are treated every year for skin cancer. They are more common in men and become more common as you get older, mainly due to sun exposure.
Less commonly, Head and Neck Cancers may occur in the salivary glands, and other tissues in the face, neck, eyes and ears.
Causes of Head and Neck Cancer
The most important risk factors for mucosal head and neck cancer are tobacco (cigarette smoking, cigars, pipes, chewing tobacco or snuff) and alcohol use.
- They are responsible for over 75% of cases and are especially important for cancers of the mouth, throat and voice box.
- Those with a long history of tobacco use, heavy tobacco use and who use both tobacco and alcohol are at a significantly higher risk of head and neck cancer.
Infection with the human papillomavirus (HPV) is also a risk factor for some types of head and neck cancer, particularly those involving the tonsils or tongue base (known as oropharyngeal cancer).
Other risk factors for head and neck cancer include increasing age, male gender, race, inhalation of certain chemicals and dusts, the Epstein-Barr Virus (EBV), chewing betel nut and possibly a diet low in fruit and vegetables.
Sun exposure is the most important risk factor for skin cancers, particularly repeated sunburn as a young adult.
Previous radiation exposure is also an important risk factor for head and neck cancer, in particular thyroid cancers. There is usually a delay of at least 10 years from the time of exposure to development of the cancer.
Some patients may not have any identifiable cause for their cancer.