Thyroid cancers are fairly rare types of cancer, accounting for 1 in 100 of all cancers, with approx. 1,100 new cases in the UK each year. They usually grow slowly.The thyroid gland is situated at the base of the throat. It absorbs iodine from the diet and produces thyroid hormones, which keep the body functioning normally.

There are three main types of cancer of the thyroid:

• Papillary: the most common type, more common in younger people, predominantly women.
• Follicular: less common found particularly in older people.
• Medullary: a rare type which is sometimes, but not always, hereditary.

The outlook for most types of thyroid cancer is generally very good and many people are completely cured of the disease, even if it has spread beyond the thyroid.

Causes

The cause of Thyroid cancer is unknown.

However:

• Evidence suggests that previous exposure of the neck area to radiation increases the risk. This may be due to radiotherapy given in childhood, or when environmental levels of radiation become high (eg due to nuclear fallout following the Chernobyl nuclear accident).
• The cancer is more common in women than men.
• Medullary thyroid cancer can be hereditary, caused by an abnormal gene, which increases the risk of developing thyroid cancer. There are screening tests available to detect the gene faults responsible.

Treatment depends on a number of factors including age, general health, the type and size of the tumour, and whether it has spread beyond the thyroid.

Possible treatments for thyroid cancer include:

• Surgery is often the main treatment for thyroid cancer. In most cases the whole thyroid gland will need to be removed (total thyroidectomy). Sometimes it is adequate to remove one lobe (partial thyroidectomy). These procedures are carried out under general anaesthetic. Depending on the type of cancer, the lymph nodes may also be removed if they contain cancer cells.
• Radioactive iodine treatment may be necessary following surgery. This will be taken as tablet, or a liquid. It is low dose radiation so treatment is monitored in hospital for a few days.
• Radiotherapy and chemotherapy may also be used to treat cancer that has spread to other parts of the body.