Thyroid Cancer: Types, Symptoms and Causes, Diagnosis, Treatment

Thyroid cancer is one type of cancer that develops in the thyroid gland. Cancer starts when cells begin to proliferate or grow uncontrollably. Thyroid cancer research is currently being conducted in a number of university hospitals, medical centres, and other institutions globally.

What is Thyroid Cancer?

Thyroid cancer starts from the thyroid gland, which is part of the endocrine system. Hormones produced by the thyroid gland regulate body temperature, heart rate, and metabolism. The most common types of thyroid cancer - papillary and follicular, respond very well to treatment. Thus, the majority of thyroid cancers are curable.

What is Thyroid Gland?

Thyroid gland is shaped like a small butterfly and is located in the lower front of the neck. It is a gland that regulates metabolism activity of the body. It also secretes hormones that control many bodily functions, such as how energy is used, heat is generated, and how oxygen is consumed.

The pituitary gland in the brain is in charge of thyroid and other endocrine glands. It is responsible for the release of thyroid-stimulating hormone (TSH). TSH, as the name implies, stimulates the thyroid gland to produce thyroid hormone. To produce these hormones, thyroid requires iodine, a mineral. Cod, tuna, dairy products, whole-grain bread, and iodized salt are examples of iodine-rich foods.

When cells change or mutate, thyroid cancer develops. The abnormal cells begin to multiply in the thyroid and, until enough of them form a tumour. Thyroid cancer is one of the most treatable types of cancer if detected early.

Types of Thyroid Cancer 

Thyroid cancer is classified based on the type of cells that mutate the cancer. The classification is as follows:

Papillary Thyroid Cancer 

Papillary thyroid cancer is the most common form of cancer. The follicular cells in the gland are affected by papillary carcinoma. It can be seen in either of the gland's two lobes, and it spreads slowly. It could spread to the lymph nodes in the neck in some situations. 

It has been found in up to 80% of all thyroid cancer cases. It spreads rapidly to the lymph nodes in the neck. Yet, the chances of recovery are good. 

Follicular Thyroid Cancer 

This type of cancer accounts for 10% to 15% of all thyroid cancers diagnosed recently. It has the potential to spread to lymph nodes as well as blood vessels.

Medullary Thyroid Cancer 

In roughly 4% of all thyroid cancer cases, medullary cancer can be found. Since it produces a hormone called calcitonin, which doctors look for in blood test results, it's more likely to be discovered early. 

It develops from the C cells found within the thyroid gland. The C cells are primarily responsible for calcitonin hormone secretion. Thyroid cancer spreads to the lymph nodes, liver, and lungs, making it difficult to find. Spontaneous medullary thyroid cancer and familial medullary thyroid cancer are two types of medullary thyroid cancer.

Anaplastic Thyroid Cancer 

This type of cancer is the most dangerous because it spreads quickly to other parts of the human body. It is rare, yet it is also the most difficult to treat. Anaplastic carcinoma, also known as undifferentiated carcinoma, is one of the rarest types of thyroid cancer and is virtually undetectable because the cancer cells look nothing like normal thyroid cells when examined under a microscope. 

Other types of thyroid diseases are extremely rare, such as thyroid sarcoma, thyroid lymphoma, and other tumours.

Symptoms and Causes of Thyroid Cancer

Thyroid cancer symptoms are noticeable at an early stage. 

Symptoms of Thyroid Cancer

Symptoms of thyroid cancer are visible during their initial phase of mutation because there are only some common symptoms at the initial stage. However, as it grows, one may encounter any of the following problems:

• Throat and neck pain
• A lump in your neck
• Difficulty swallowing
• Hoarseness and vocal changes
• Cough

Causes of Thyroid Cancer 

Experts are baffled as to why some cells develop cancer (malignant) and attack the thyroid. Certain factors, such as radiation exposure, a low-iodine diet, and faulty genes, can raise the risk.

• Inherited Genetic Syndrome - Some diseases, including cancer, are caused by the DNA you inherit from your parents. In 2 out of 10 cases of medullary thyroid cancer, it is caused due to an inherited abnormal gene.
• Radiation exposure -  If you got radiation treatment for your head or neck as a child.
• Iodine deficiency - If you don't get enough of this chemical element in your diet, you may be more prone to certain types of thyroid cancer. Iodine deficiency may lead to goitre.

Diagnosis of Thyroid Cancer

If a patient has an enlarged thyroid nodule or shows other symptoms of thyroid cancer, the doctor may suggest one or more of the following tests:

• Thyroid Blood Tests- It checks hormone levels and determines whether your thyroid is functioning properly.
• Biopsy- A fine-needle aspiration biopsy is a procedure in which your doctor or healthcare provider removes cells from your thyroid to test for cancer cells. If cancer cells have spread to lymph nodes, a sentinel node biopsy can determine this. Ultrasound technology may be used by your provider to guide these biopsy procedures.
• A Radioiodine Scan - It can detect thyroid cancer and determine if it has spread. You take a pill that contains a small amount of radioactive iodine (radioiodine). In a few hours, the thyroid gland absorbs the iodine. A special device is used by your healthcare provider to measure the amount of radiation in the gland. More testing is required to confirm the presence of cancer in areas with lower levels of radioactivity.
• Imaging Scans: Scans like MRI(Magnetic resonance imaging), CT scan (Computed Tomography) and PET (Positron Emission Tomography) can find thyroid cancer.

Treatments of Thyroid Cancer

Some of the most commonly practiced treatments are as follows:

• Surgery is the most commonly used treatment to manage or deal with thyroid cancer. Depending on the size and location, your surgeon may remove a part of the thyroid gland (lobectomy) or the entire gland (thyroidectomy). In addition, any nearby lymph nodes where cancer cells have spread can also be removed by your surgeon.
• Radioiodine therapy entails swallowing a pill or liquid containing a higher dose of radioactive iodine than is used in a diagnostic radioiodine scan. The radioiodine shrinks and kills cancer cells as well as the diseased thyroid gland. Don't be alarmed — this treatment is fully risk-free. Almost all of the radioiodine is absorbed by your thyroid gland. The rest of your body is only exposed to a small amount of radiation.
• Radiation therapy - Radiation therapy kills cancer cells and prevents their growth. External radiation therapy employs the use of a machine to direct powerful beams of energy directly to the tumour site. Internal radiation therapy (brachytherapy) involves implanting radioactive seeds within or near the tumour.
• Chemotherapy - Chemotherapy drugs, administered intravenously or orally, kill cancer cells and stop tumour growth. Only a small percentage of patients with thyroid cancer will ever require chemotherapy.
• Hormone therapy - This treatment prevents the release of hormones that cause cancer to spread or return.

Things to Remember

• Thyroid cancer is the most familiar type of endocrine cancer.
• The thyroid gland is a ductless endocrine gland located in the front of the neck.
• Thyroid cancer is the second most common type of cancer found in pregnant women.
• Hypothyroidism, also known as underactive thyroid disease, is a common condition of a thyroid.
• Hyperthyroidism is caused by an excessive production of thyroxine hormone.