Thyroid Cancer

What is thyroid cancer?

Thyroid cancer is rare cancer that affects the thyroid gland, a small gland at the base of the neck. The thyroid gland is responsible for producing hormones which regulate the heart rate, blood pressure, body temperature and weight.

What are thyroid cancer symptoms?

The most common presenting symptom of thyroid cancer is a painless lump in the neck. Other symptoms usually indicate more advanced disease and include:

• pain in the neck and throat
• new-onset hoarseness
• difficulty in swallowing or breathing
• Swollen lymph nodes in your neck

The diagnosis of thyroid cancer depends on a good history, the interpretation of the thyroid ultrasound findings and most importantly a fine needle aspiration of the lump to obtain cells for evaluation by a cytopathologist. In some cases, surgery might be necessary to confirm or exclude cancer.

There are four subtypes of thyroid cancer:

• Papillary thyroid cancer
  this is the most common type of thyroid cancer which occurs in the follicular cells that produce and store thyroid hormones. It usually affects people under 40, particularly women
• Follicular thyroid cancer
  this cancer also occurs in follicular cells of the thyroid gland. It accounts for 10% of cases of thyroid cancer and tends to affect older adults
• Medullary thyroid cancer
  accounts for 7% of cases; unlike the other types of thyroid cancer, medullary thyroid cancer can be hereditary. It occurs in the thyroid cells called the C cells, which are responsible for producing the calcitonin hormone.
• Anaplastic thyroid cancer
  is the rarest and most aggressive type of thyroid cancer that occurs in the follicular cells. In most cases it affects older people aged 60-80 years.

What are the treatment options?

Once cancer has been diagnosed, the treatment will consist of surgery followed by radioactive iodine.

Surgery for thyroid cancer will entail either removing half of the thyroid gland (thyroid lobectomy) or all of the thyroid gland (total thyroidectomy). Surgery is done under general anaesthesia and will leave a small scar at the base of the neck. The following complications may occur after a thyroidectomy:

• Hypothyroidism:
  May be unavoidable and a consequence rather than a complication when a total thyroidectomy is done. It will require life-long hormone (thyroxine) supplementation.
• Recurrent laryngeal nerve injury will result in hoarseness (1 per 100 cases) which in most cases will be temporary but can be permanent.
• Hypoparathyroidism: the 4 parathyroid glands lie in close proximity to the thyroid and can be damaged during surgery, especially if the thyroid is completely removed. This will result in low calcium levels which once again can be transient or permanent.
• Bleeding/haematoma: a small amount of post-operative bleeding can lead to pressure on the trachea with airway compromise.

Radioactive iodine treatment: After having thyroid surgery for cancer, Dr Cooper will refer you to an oncologist who may recommend a course of radioactive iodine treatment to help destroy any remaining cancer cells in your body and prevent cancer from recurring.