Thyroid cancer

Follicular cell thyroid cancers, which begin in the follicular cells in the thyroid, are much more common than medullary thyroid cancers which begin in cells called parafollicular cells (C cells) in the thyroid.

Thyroid cancer is also identified by the way the cells appear. If the cancer cells look like healthy cells, they are called well differentiated cells. If the cancer cells don't look much like healthy cells, they are called poorly differentiated or undifferentiated (anaplastic). Usually poorly differentiated/undifferentiated cells are harder to treat than well differentiated cells because the cells have developed additional mutations.

Follicular cell thyroid cancer

There are 5 main types of follicular cell thyroid cancers including

• papillary thyroid cancer
• follicular thyroid cancer
• Hürthle cell thyroid cancer
• poorly differentiated thyroid cancer
• anaplastic thyroid cancer

Papillary thyroid cancer is the most common type of thyroid cancer making up 80% of all cases. Papillary thyroid cancer is also the most common in women who have not reached menopause.

Poorly differentiated thyroid cancer and anaplastic thyroid cancer are more aggressive than the other subtypes of follicular cell thyroid cancers and are more likely to spread to other parts of the body.

Medullary thyroid cancer (MTC)

Medullary thyroid cancer (MTC) only account for 3-10% of all thyroid cancers. MTC produces proteins in the blood called carcinoembryonic antigen (CEA) that can be measured in the blood to determine how well the cancer is responding to treatment.

There are two subtypes within MTC as well:

• sporadic MTC
• familial MTC

Sporadic MTC is the type of MTC is not inherited from your parents and accounts for the majority of cases (85%).

Familial MTC is usually found in children and young adults and is connected to a gene that can be passed down from your parents, so it's important to get genetic testing if your parents have a mutation in the RET gene.

What are the risks?

A few other risk factors of developing thryoid cancer apart from being a woman include

• those between the ages of 20-55
• radiation exposure from things such as dental x-rays or working at a nuclear power plant
• inherited family disorder in the RET gene
• a lack of Iodine (salt) in the diet

How do I know if I have it?

To diagnose thyroid cancer the doctor will usually examine your neck first and order blood tests to see how your thyroid is functioning. This might be followed by an imaging test such as an ultrasound, CT or MRI to check for any abnormalities seen in the thyroid.

If anything abnormal is found, the medical professional will likely do a biopsy (tissue sample) of the thyroid to test for any cancerous cells.

I have it. Now what?

There are quite a few options of treatment after surgery to ensure that all the cancer cells have been killed.

Thyroid hormone therapy is a medication often used after surgery to supply your body with the hormone that the thyroid is no longer making. This medication also stops the production of TSH (thyroid-stimulating hormone) which can cause the cancer cells to grow. People who start this medication may stay on it for the rest of their lives.

Radioactive iodine is also common for thyroid cancer patients after surgery. The radioactive iodine can be taken as a pill or as liquid to be swallowed which helps destroy any remaining cancer cells left in the body. You may have to isolate for a few days after treatment to allow the radiation to leave your body as it can be harmful for people you come into contact with.

If your type of thyroid cancer is more likely to return, the doctor may also suggest external radiation using a machine with high-energy beams. For thyroid cancer that is more advanced or aggressive, both chemotherapy and targeted drug therapy will be options for treatment.

Chemotherapy can be used for anaplastic thyroid cancer, but is not commonly used with other cancers.

Targeted drug therapy will identify weaknesses within the cancer cells and target these cells in order to kill them.

Lastly, if surgery is not an option but the cancer tumor is small, you might be able to inject alcohol into the cancer cells with an ultrasound machine that can effectively kill the cancer cells.