Understanding Thyroid Cancer

What is thyroid cancer?

Thyroid cancer is defined as an abnormal and uncontrolled proliferation of thyroid cells in the thyroid gland.

The thyroid gland is a butterfly-shaped gland located in front of your neck just below the voice box (larynx). It is responsible for the production and secretion of thyroid hormones that help regulate your body’s metabolism such as heart rate, breathing, body temperature, weight, blood pressure, and several other bodily functions.

Most cases of thyroid cancer are usually treatable and to a large extent completely curable, although there is a slight chance of relapse despite successful completion of treatment. Women are 2 to 3 times more likely than men to develop thyroid cancer and the risk of developing it increases as you age.

Types of thyroid cancer

Thyroid cancer can be divided into 4 main types:

  • Papillary thyroid cancer: This is the most common type of thyroid cancer that accounts for around 80% of all thyroid cancer cases. This type of cancer spreads slowly and mostly to the lymph nodes in the neck. It is less dangerous and completely treatable and normally affects individuals below 40 years of age, especially women.
  • Follicular thyroid cancer: This type of cancer accounts for around 10% to 15% of all thyroid cancer cases and is the type of cancer that is likely to spread and recur. It normally affects people over 50 years of age, especially women. This cancer can travel through the bloodstream to other parts of the body such as bones or lungs.
  • Medullary thyroid cancer: This type of cancer accounts for around 4% of all thyroid cancer cases. You are more likely to develop this type of cancer if you have a familial history or certain genetic conditions. This cancer can be detected at an early stage via blood test as it produces increased levels of calcitonin in the bloodstream.
  • Anaplastic thyroid cancer: This is a rare and more serious type of thyroid cancer that accounts for around 1% of all thyroid cancer cases. It spreads rapidly to other parts of the body and is extremely difficult to treat. It usually affects people aged 60 and over.

Causes of thyroid cancer

It is unclear what exactly causes thyroid cancer. However, there are several risk factors that can increase your chances of developing thyroid cancer, such as:

  • Inherited genetic conditions
  • Exposure to radiation treatment
  • Being a woman
  • Advanced age
  • Overweight and obesity
  • Acromegaly (excessive secretion of growth hormone by body)
  • Having other thyroid conditions, such as thyroiditis or goitre
  • Iodine deficiency

Symptoms of thyroid cancer

In most cases, symptoms can be difficult to determine in the early stages of thyroid cancer. However, as the thyroid cancer grows, you may notice symptoms such as:

  • Difficulty swallowing
  • Difficulty breathing
  • Hoarseness
  • Lump in the neck
  • Sore throat
  • Cough
  • Pain in the base of the neck
  • Swollen lymph nodes, particularly in the neck

Diagnosis of thyroid cancer

Some of the tests and procedures involved in the diagnosis of thyroid cancer include:

  • Physical exam: Your physician will examine your neck to check for signs of lumps or nodules or enlargement of the thyroid gland.
  • Ultrasound of the thyroid: This test uses sound waves to create images of your thyroid. The test utilises a lubricating gel and a device called a transducer to gently move over your neck to look at the size and texture of the thyroid gland. This test can indicate whether the nodule is a fluid-filled cyst or a solid mass of tissue.
  • Fine-needle aspiration (FNA) biopsy: During this biopsy, your doctor uses a fine needle to withdraw a sample of the suspicious thyroid nodule under ultrasound guidance. The obtained sample is then examined under a microscope to determine if the nodule is noncancerous or cancerous in nature.
  • Other imaging tests/scans: PET scan, CT scan, MRI, and radioiodine scan may be used to determine the location, size, and spread of the thyroid cancer.
  • Genetic testing to look for specific genes that may increase your chances of cancer.

Treatment for thyroid cancer

Treatment for thyroid cancer depends upon the stage and type of the cancer and may involve the following methods:

  • Thyroidectomy: This is the main treatment for most cases of thyroid cancer and involves the surgical removal of the tumour; or all or part of the remaining thyroid gland. During the surgery, the adjoining lymph nodes in the neck may also be removed if the cancer has spread or likely to spread to the lymph nodes. For small cancers, removal of half of the thyroid gland might be adequate to control the disease.
  • Radioactive iodine treatment: During this method, high doses of radioactive iodine are administered orally. The radioactive substance travels through your blood and destroys the cancer cells without harming any healthy tissue.
  • Hormone therapy: In this therapy, certain hormone medications are used to prevent the release of specific internal hormone (TSH) that can cause the growth of the cancer.