Medullary thyroid cancer (MTC) accounts for around 1-2% of all thyroid cancers and it can affect people of all ages.

There are two main types of medullary thyroid cancer:

  • Sporadic type accounts for 75-80% of all cases of MTC. It usually affects adults.

  • Familial (inherited) type accounts for 25-30% of all cases of MTC and it can occur at any age. This kind of medullary thyroid cancer is due to an inherited gene called RET and it carries a 50% risk of being passed on to children.

Research into genetics over the past few years has transformed our understanding of how medullary thyroid cancer develops. There are various sub-types of this kind of cancer, based on different genetic changes that can affect different cells in the body, and which can cause other tumours or conditions to develop alongside medullary thyroid cancer.

Genetic testing is now recommended for everyone with a diagnosis of medullary thyroid cancer as it helps identify the most suitable treatment options for MTC and any other conditions, and it also confirms if there is a chance of the cancer being passed on to children.

Nearly everyone who shows the genetic changes associated with familial medullary thyroid cancer will eventually develop the disease - pre-emptive surgical removal of the thyroid gland can therefore be recommended.

If you have a family history of medullary thyroid cancer, speak to your doctor, nurse or healthcare professional to discuss the availability of genetic testing.


If your cancer has spread to local tissue in the neck and if you start experiencing symptoms associated with this, or if your cancer has spread to other parts of the body, your doctor might talk to you about radiotherapy. The exact course of treatment will be explained by your doctor and will depend on several factors including your general health and the severity (grade) of cancer. Radiotherapy can be outside the body (external beam radiation) or internal.

External beam radiation can cause local irritation and swelling for a few weeks after treatment. You may notice skin irritation, sore gums, a hoarse voice or a swollen throat. These symptoms can usually be managed relatively easily and fade after a few weeks although more severe symptoms can occur, making eating and drinking difficult.

Targeted therapy (also known as systemic therapy)

If your medullary thyroid cancer is advanced and actively progressing, targeted therapy might be suitable. Two targeted medicines, called tyrosine kinase inhibitors, have recently been approved for use in Europe, America and some other parts of the world. These medicines are taken every day in tablet form and can delay cancer progression. However, these TKIs have specific profiles of side effects that can be significant and some people need a reduced dose in order to make the side effects manageable.1

Your doctor will also need to take regular blood samples to check the level of thyroid stimulating hormone (TSH) as these medicines can cause hypothyroidism, characterised by elevated TSH levels.