Thyroid Cancer

Thyroid cancers are relatively rare and develop from cells of the thyroid gland.  If the cancer is not treated, cancer cells from the original site may break away and spread to other parts of the body.

Contributing Risk Factors

Risk factors include:

• Gender – Thyroid cancer is slightly more common in women than in men.
• Radiation – People who have had radiotherapy applied to their neck, or who work with certain radioactive substances (e.g. nuclear industry workers, scientists or students) have an increased risk of thyroid cancer later in life (often 10-30 years later).  This risk is highest when treatment took place at a young age.  There was a high incidence of thyroid cancer in Belarusian and Ukrainian children who have been exposed to radiation after the Chernobyl accident.
• Genetic conditions – About 1 in 10 people with a certain type of thyroid cancer called medullary thyroid cancer carry an abnormal gene.  This condition is known as MEN2 syndrome.  They may pass the gene on to the next generation.  A family member with this genetic defect is at an increased risk of developing thyroid cancer.

Signs and Symptoms

Symptoms may vary, and are not unique to thyroid cancer.  They include a lump in the neck that gradually increases in size, with or without pain; difficulties swallowing or breathing – this can happen occasionally as a result of the cancer pressing on the esophagus or trachea (windpipe).

Diagnosis and Tests

Diagnosis may involve the following:

• Having some blood taken to check thyroid hormone levels.
• An ultrasound scan to look at the thyroid and neck and determine whether there are lots of lumps or just one, and whether the lumps are solid or filled with fluid (cysts).  A single, solid lump is most likely to be cancer.  An ultrasound may also be used to help find the thyroid lump during a needle biopsy.
• A needle biopsy, used to obtain a small amount of thyroid tissue, which can be looked at under a microscope.  This is the only way to be sure if a lump is cancer or not.