Thyroid Cancer: An Overview

What is Thyroid Cancer?

Thyroid cancer affects the cells of the thyroid. The thyroid is a gland present in the base of the neck area, below the thyroid cartilage, also known as adam’s apple. It is a butterfly-shaped organ that cannot be felt or seen from the surface of the skin. The thyroid gland has two types of cells: follicular cells – help in making thyroid hormone by using iodine in the blood, and C cells – produce calcitonin, which controls calcium levels in the body. Thyroid cancer can occur in many types and growths. Thyroid cancer types can be benign (does not spread) or malignant (spreads to other areas). There are four types of thyroid cancer – papillary, follicular thyroid cancer, medullary, and anaplastic thyroid cancer.

What are the symptoms of thyroid cancer?

Thyroid cancer can often go unnoticed because thyroid cancer symptoms and signs are rare, at least in the early stages. Some of the common symptoms include:

• Difficulty and pain during swallowing
• A lump felt on the skin at the base of the neck
• Swollen lumps around the neck area
• Throat pain

What Causes Thyroid Cancer?

It is not clear what exactly causes thyroid cancer. There can be many reasons, including:

• Family history of thyroid cancer: If a person has a close relative, such as a parent or sibling, who has had thyroid cancer, they may be more likely to develop the disease themselves. This could be due to shared genetic factors or environmental influences within the family.
• Genetic mutation: Another possible cause of thyroid cancer is a genetic mutation that may have occurred as a result of environmental or lifestyle factors. For example, exposure to radiation or certain chemicals may increase the likelihood of genetic mutations that can lead to cancer. Lifestyle factors such as smoking or a poor diet may also contribute to the development of genetic mutations that can increase cancer risk.
• Iodine deficiency: The thyroid gland requires iodine to produce hormones, and a lack of iodine in the diet can lead to an enlarged thyroid gland, a condition known as goitre. Over time, this can increase the risk of thyroid cancer.

Radiation exposure: Exposure to radiation is a known risk factor for thyroid cancer. This can include exposure to medical radiation during diagnostic procedures, as well as exposure to radiation from nuclear accidents or weapons testing. Children who are exposed to radiation are particularly vulnerable to developing thyroid cancer later in life.

How Many Stages in Thyroid Cancer?

The stages of thyroid cancer are based on where the tumour is located and its spread to other nearby organs. Thyroid cancer stages are as follows:

• Stage 0: It is the beginning of cancer. It has the potential to cause cancer. This is also known as the “carcinoma in situ” stage, where abnormal cells are found in the thyroid gland but haven’t spread to nearby tissue or organs. This stage has the potential to become cancerous and requires close monitoring and treatment.
• Stage 1: At this stage, the cancer is localised to the thyroid gland and is less than 2 centimetres in diameter. It has not spread beyond the thyroid gland.
• Stage 2: The cancer has grown larger than 2 centimetres but is still confined to the thyroid gland.
• Stage 3: At this stage, the cancer has spread beyond the thyroid gland to nearby lymph nodes or other tissues in the neck. Stage 1 to 3 is defined by the size of the tumour.
• Stage 4: This is the most advanced stage of thyroid cancer. The cancer has spread to other parts of the body, such as the lungs or bones. Stage 4 thyroid cancer symptoms include swollen lymph nodes, pain in neck and throat, lump that can be felt through the skin, difficulty in swallowing and others.

How is Thyroid Cancer diagnosed?

A physician performs a physical examination first to check for signs of cancer. Then various laboratory examinations are done to confirm the diagnosis of Thyroid Cancer. Some tests include CT, MRI, a biopsy of thyroid tissue, blood tests, ultrasound, and genetic testing. All of them are not required for diagnosis.

1. CT (Computed Tomography): It uses X-rays to create detailed multiple images of the body’s internal structures to identify the size, location, and spread of thyroid cancer to nearby lymph nodes or other tissues
2. MRI (Magnetic Resonance Imaging): It uses a magnetic field and radio waves to create detailed images of the body’s internal structures to detect the size and location of thyroid tumours and to evaluate the spread of cancer to nearby lymph nodes or other tissues.
3. Biopsy of thyroid tissue: A small tissue sample is removed from the thyroid gland for examination under a microscope
4. Blood tests: Blood samples are taken and analysed to check thyroid hormone levels and to look for specific markers of thyroid cancer, such as thyroglobulin or calcitonin
5. Ultrasound: It uses high-frequency sound waves to create images of the body’s internal organs.

What is the Treatment for Thyroid Cancer?

Thyroid cancer treatment depends on the stage and the type of the tumour. Surgery is most commonly done to remove the tumour. If the thyroid gland is removed fully or partially (small part), it’s called thyroidectomy. Chemotherapy, radioactive iodine, radiation therapy, supportive care, etc., are other forms of treatment. Some of the thyroid cancer treatment options include:

• Surgery: It is the most common treatment for thyroid cancer, and it involves removing the tumour and possibly the surrounding thyroid tissue.
• Radioactive iodine therapy: It uses radioactive iodine to destroy any remaining thyroid tissue after surgery or to treat cancer that has spread to other parts of the body.
• External beam radiation therapy: It uses high-energy radiation to kill cancer cells, which are directed at the cancerous tumour from outside the body.
• Chemotherapy: It is not usually effective in treating thyroid cancer, but it may be used in rare cases when the cancer is not responding to other treatments.
• Targeted therapy: It is a type of treatment that targets specific proteins or genes that are involved in the growth and spread of cancer cells. It involves the use of drugs that interfere with the signals that cancer cells need to grow and divide.
• Thyroid hormone therapy: It involves taking synthetic thyroid hormone to replace the hormones that the thyroid gland would normally produce. It is used to suppress the growth of any remaining cancer cells and to prevent the cancer from coming back.
• Supportive care: In addition to these treatments, patients with thyroid cancer may also receive supportive care to manage symptoms and side effects. Supportive care can include pain management, anti-nausea medication, and antibiotics.

Is Thyroid Cancer Curable?

Most types of thyroid cancers are curable, especially if they are diagnosed at early stages. Some types of thyroid cancers grow slowly, so they can be easily treated. However, thyroid cancers, such as medullary thyroid cancer and anaplastic thyroid cancer, have low survival rates. Thyroid cancer survival rates vary from person to person based on the stage in which the cancer is diagnosed and the patient’s overall health.

Can thyroid cancer cause dizziness?

Dizziness is not a direct symptom of thyroid cancer. But if the thyroid cancer cells spread to different parts of the brain such as the cerebellum, dizziness and various other brain-related symptoms may occur.

Can thyroid cancer cause headaches?

The thyroid gland is responsible for making and releasing thyroid hormones. The thyroid hormone is very important for many activities and metabolism in the body. Changes to thyroid hormone levels can sometimes cause headaches and even migraines. In thyroid cancer, if the thyroid hormone levels vary, a headache can occur.

Is papillary thyroid cancer deadly?

Papillary thyroid cancer is the most common type of thyroid cancer with around 80% of thyroid cancers are papillary thyroid cancers. Fortunately, it is easily curable, even though it spreads to adjacent lymph nodes. This type of thyroid cancer is rarely fatal.

Can males get thyroid cancer?

Yes, males can get thyroid cancer. But women tend to get thyroid cancer more commonly compared to men. Women also tend to get it in their 40’s and 50’s, whereas for men, it can be later stages of life, like in their 60’s and 70’s.

Can you live without a thyroid gland?

Yes, you can live without the thyroid gland. Thyroid cancers or some thyroid diseases require the removal of the thyroid gland. In such cases, supplemental thyroid hormone is given to the patients to maintain its levels in the blood. It is lifelong hormone replacement therapy. Its dose and the thyroid blood levels should be frequently monitored.

References:

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2712461/
• https://www.endocrineweb.com/conditions/thyroid-cancer/thyroid-cancer
• https://www.mayoclinic.org/diseases-conditions/thyroid-cancer/diagnosis-treatment/drc-20354167
• https://www.cancer.net/cancer-types/thyroid-cancer/stages
• https://www.cancer.org/cancer/thyroid-cancer/about/what-is-thyroid-cancer.html