Thyroid cancer

What is thyroid cancer?

The thyroid gland is a butterfly-shaped structure found at the base of your neck which is responsible for producing thyroid hormones T3, T4 and calcitonin. T3 and T4 act to regulate your metabolism whilst calcitonin helps control the amount of calcium that circulates. 

Sometimes the cells that make up the thyroid gland grow at a very fast rate, which means they change and become cancerous. Most changes that occur respond very well to treatment, though there are some types that are more resistant to treatment and may take longer to treat. 

What are the different types of thyroid cancer?

1. Differentiated thyroid cancer – this is the most common type and it includes the following subtypes: 

   • Papillary – this is the most common cause of differentiated thyroid cancer. It can present with a small lump on the neck which slowly gets bigger. It’s most likely to affect patients under the age of 40, and is most common in women. If it spreads, it usually spreads to areas around the thyroid gland. 

   • Follicular – this is less common, and more likely to be found in those who are aged 40 to 60. If it spreads, it’s more likely to spread to structures further away from the thyroid gland, such as the bones or the lungs.

2. Medullary thyroid cancer – this type is less common, accounting for less than 2% of cases, and typically affects both men and women. Unlike other types of thyroid cancer, medullary thyroid cancer can run in families.

3. Anaplastic thyroid cancer – this is the least common type of thyroid cancer but the most serious. It’s more likely to affect people over the age of 60.

What are the symptoms of thyroid cancer?

Some of the symptoms that can indicate you have thyroid cancer are also common symptoms seen in many other conditions, so it’s always important to speak to a GP if you have any of the following: 

• A lump in your neck – this is usually painless

• A lump in your neck that changes size  

• A change to your voice which lasts longer than 3 weeks. You may notice your voice has become deeper or more hoarse

• A sore throat

• Difficulty swallowing which does not improve

Symptoms that indicate medullary thyroid cancer are more generalised, and can include going to the toilet more often or unexpectedly going red in the face. 

What causes thyroid cancer?

Unfortunately, the main cause of thyroid cancer is still largely unknown, but there are some risk factors that can increase your chance of developing thyroid cancer. 

Having these risk factors does not directly cause cancer to develop but may influence your likelihood of developing it: 

• Age and sex – thyroid cancer is more likely to develop in women of reproductive age. 

• Being overweight

• Having had a previous thyroid condition, such as an enlarged thyroid gland (known as a goitre), thyroid nodules, or Hashimoto’s disease (a disease where your immune system attacks your thyroid gland)

• If a family member has had thyroid cancer

• Genetics – if you’ve inherited faulty genes you have an increased likelihood of developing medullary thyroid cancer

• Radiation therapy – if you’ve had previous radiation therapy to the neck area

• Having had other types of cancer previously, such as breast cancer or testicular cancer

How is thyroid cancer diagnosed?

If you feel you have symptoms of thyroid cancer, the most important thing is to see a GP in the first instance. 

If they feel you meet the criteria, you’ll be referred urgently to a specialist. Your specialist may refer you for specific tests which may include: 

• Blood tests to measure your hormone levels for an assessment of how active your thyroid gland is

• An ultrasound scan of the thyroid gland – this will create an image of the thyroid gland, so a specialist can see whether there’s a single lump or multiple lumps

• A sample of cells may need to be taken from the thyroid so that they can be checked in the lab for any abnormality

• An MRI or a CT scan

How is thyroid cancer treated?

Treatment usually depends on a few factors, which include: 

• Where the cancer is 

• The type of thyroid cancer 

• Whether the cancer remains in the thyroid gland or has spread

The most common treatment option is surgery. This can involve either removing the whole thyroid gland or part of it, and both these procedures would normally be performed under general anaesthetic. After this procedure, it’s likely you’ll have thyroid hormone replacement. 

Another option for certain types of thyroid cancer is radioactive iodine treatment. The radiation from the iodine works to kill the cancerous cells. 

Other options include external radiotherapy or chemotherapy. 

When should I seek help?

If you have any symptoms of thyroid cancer, the best thing to do is to seek medical advice. Although only 5% of neck lumps are cancerous, a GP can advise you if you have any suspicions.