Thyroid Cancer : Type, Symptom, Risk Factor, Diagnosis, Stage, Treatment, And Drug

Thyroid Cancer is a cancer that begins in the thyroid gland.The thyroid is a large ductless gland in the neck that secrets hormones regulating growth and development through the rate of metabolism.The thyroid gland has two main types of cells.Follicular cells use iodine from the blood to make thyroid hormones, which help in regulating a person's metabolism.Parafollicular cells make calcitonin that a hormone helps in controlling how the body uses calcium.Thyroid nodules are lumps or bumps in the thyroid gland.The thyroid cannot be felt and seen in the most people.

The Types of Thyroid Cancers

1. Differentiated Thyroid Cancer

• Papillary Thyroid Cancer (PTC) tends to grow very slowly and usually develops in only one lobe of the thyroid gland.
• Follicular Thyroid Cancer (FTC) spreads to other parts of body, such as the bones and lungs.

2. Undifferentiated Thyroid Cancer

• Medullary Thyroid Cancer (MTC) develops from the follicular cells of the thyroid gland.Sometimes it can spread into lymph nodes, the lungs or liver even before a thyroid nodule is discovered.
• Anaplastic Thyroid Cancer (ATC) often spreads quickly into the neck and to other parts of the body.It sometimes develops from an existing palpillary or follicular cancer.It is very difficult to treat.

The Signs or Symptoms of Thyroid Cancer

• A lump in front of the neck , sometimes growing quickly.
• Swollen glands in the neck.
• Pain in the throat or neck, sometimes going up to the ears.
• Hoarseness.
• Difficulty in swallowing.
• Trouble breathing.
• A constant cough that is not due to a cold.

The Risk Factors of Thyroid Cancer

• Age
• Gender
• Family history of thyroid cancer
• A diet low in iodine
• Exposure to ionizing radiation
• Certain inherited medical conditions, such as cowden disease, corney complex type I, familial adenomatous polyposis (FAP)

Diagnosis

Some tests are performed to diagnose the thyroid cancer as follow :

• Medical history and physical exam are to get more informations about family of having thyroid cancer and examine possible symptoms of thyroid cancer and any other health problems.
• Biopsy is a test in which cells from the suspicious area are removed and looked under a microscope.
• Computed Tomography (CT) scan produces detailed cross-sectional images of the body and determines the location and size of thyroid cancer and whether they have spread to nearby areas.
• Magnetic Resonance Imaging (MRI) scan provides very detailed images of thyroid gland and looks for cancer in the thyroid or cancer that has spread to nearby parts of body.
• Positron Emission Tomography (PET) scan is a radioactive substance is injected into the blood.
• Ultra sound uses sound waves to create images of parts of the body.It can determine if a thyroid nodule is solid or filled with fluid.
• Radioiodine scan is to determine if someone with a lump in the neck might have thyroid cancer.
• Chest X-Ray is to see if cancer has spread to the lungs.
• Vocal Cord Exam (Laryngoscopy) is a procedure to see if the vocal cords are moving normally.
• Blood Tests help in showing if the thyroid is working normally.Carcinoembryonic antingen (CEA) is high blood levels of  a protein.Test for CEA sometimes helps in finding medullary thyroid cancer.Thyroid-stimulating hormone (TSH) is blood test to check the overall activity of the thyroid gland.

THE STAGES OF THYROID CANCER

The Stages of Papillary and Follicular Thyroid Cancers in patients younger than 45 years old

• Stage I : The tumor is any size, may be in the thyroid or may have spread to nearby tissues and lymph nodes.Cancer has not spread into the other parts of the body.
• Stage II : The tumor is any size and has spread from the thyroid into the other parts of the body, such as the lungs, or bone and may have spread to lymph nodes

The Stages of Papillary and Follicular Thyroid Cancers in patients 45 years old and older

• Stage I  : Cancer is found only in the thyroid.Cancer is 2 centimeters or smaller.

• Stage II : Cancer is found only in the thyroid.Cancer is larger than 2 centimeters but not larger than 4 centimeters.
• Stage III : Cancer is found only in the thyroid and cancer is larger than 4 centimeters or cancer is any size and has spread to tissues just outside the thyroid, but not to lymph nodes.

• Stage IVA : Cancer is any size and has spread to tissue just outside the thyroid.Cancer has spread to lymph nodes on one or both sides of the neck or between the lungs.

• Stage IVB : Cancer has spread to the tissue in front of the spinal column or has surrounded the carotid artery or the blood vessels in the area between the lungs.Cancer may have spread to lymph nodes.

• Stage IVC : Cancer is any size and has spread to other parts of the body, such as the lungs and the bones.Cancer may have spread to lymph nodes.

The Stages of Medullary Thyroid Cancer for All Ages

• Stage 0 : There is no cancer found in the thyroid.
• Stage I : Cancer is found only in the thyroid.Cancer is 2 centimeters or smaller.
• Stage II : Cancer is found only in the thyroid.Cancer is larger than 2 centimeters or cancer has spread to tissues just outside the thyroid, but not to lymph nodes.
• Stage III : Cancer is any size and has spread to lymph nodes near the trachea and the larynx.Cancer may have spread to tissues just outside the thyroid.
• Stage IVA : Cancer is any size and has spread to tissue just outside the thyroid.Cancer has spread to lymph nodes on one or both sides of the neck or between the lungs.
• Stage IVB : Cancer has spread to the tissue in front of the spinal column or has surrounded the carotid artery or the blood vessels in the area between the lungs.Cancer may have spread to lymph nodes.
• Stage IVC : Cancer is any size and has spread to other parts of the body, such as the lungs and the bones.Cancer may have spread to lymph nodes.

Anaplastic Thyroid Cancer is considered in Stage IV

Anaplastic thyroid cancer grows rapidly.It usually spread within the neck when it is found.

• Stage IVA : Cancer is found in the thyroid and may have spread to lymph nodes.
• Stage IVB : Cancer has spread to tissue just outside the thyroid and may have spread to lymph nodes.
• Stage IVC : Cancer has spread to other parts of the body, such as the lungs and the bones.Cancer may have spread to lymph nodes.

TREATMENT OF THYROID CANCER

The Treatments of Papillary and Follicular Thyroid Cancers in Stage I and Stage II include

• Total or Near-Total Thyroidectomy with or without Radioactive Iodine Therapy.
• Lobectomy or removal of lymph nodes that contain cancer, followed by Hormone Therapy.
• Radioactive Iodine Therapy may be given following surgery.

The Treatments of Papillary and Follicular Thyroid Cancers in Stage III include

• Total Thyroidectomy
• Radioactive Iodine Therapy or External Radiation Therapy may be given after surgery.

The Treatments of Papillary and Follicular Thyroid Cancers in Stage IV include

Cancer has spread to lymph nodes can be treated.Cancer has spread to other parts of the body, such as the lungs and the bones cannot be treated but can relieve the symptoms and can improve the quality of life.The treatments can be done as follow :

Tumors that take up iodine

• Radioactive Iodine Therapy

Tumors that do not take up iodine

• Hormone Therapy.
• Targeted Therapy with a tyrosine kinase inhibitor (sorafenib).
• Surgery by removing cancer from areas where it has spread.
• External-Beam Radiation Therapy.
• A clinical trial of Chemotherapy
• A clinical trial of Targeted Therapy.

The Treatment of Medullary Thyroid Cancer includes

• Total Thyroidectomy if the cancer has not spread to other parts of body.
• Removal of lymph nodes that contain cancer.
• External Radiation Therapy as palliative therapy to relieve symptoms and improve the quality of life for patients whose cancer has recurred in the thyroid.
• Targeted Therapy with a tyrosine kinase inhibitor (vandetanib) for cancer has spread to other parts of body.
• Chemotherapy as palliative therapy to relieve symptoms and improve the quality of life for patients whose cancer has spread to other parts of body.

The Treatment of Anaplastic Thyroid Cancer includes

• Tracheostomy as palliative therapy to relieve symptoms and improve the quality of life.
• Total Thyroidectomy as palliative therapy to relieve symptoms and improve the quality of life for patients whose cancer has not spread away from the thyroid.
• External Radiation Therapy.
• Chemotherapy
• A clinical trial of Total Thyroidectomy followed by Chemotherapy and Radiation Therapy.

The Standard Treatment For Cancer

1. Surgery is to treat thyroid cancer.

• Lobectomy is removal of lobe in which thyroid cancer is found.
• Near-Total Thyroidectomy is removal of all but a very small part of the thyroid.
• Total Thyroidectomy is removal of the whole thyroid.
• Lymphadenectomy is removal of lymph nodes in the neck that contain cancer.

2. Radiation Therapy is a treatment that uses high-energy x-ray or other types of radiation to kill cancer cells or keep them from growing.There are two types of radiation therapy.External radiation therapy uses a machine outside the body to send radiation toward the cancer.Internal radiation therapy uses a radiactive substance sealed in needles, seeds, wires or catheters that are placed directly into or near the cancer.

3. Chemotherapy is a treatment that uses drugs to stop the growth of cancer cells either by killing the cells or by stopping them from dividing.

4. Thyroid Hormone Therapy is a treatment that removes hormones or blocks their action and stops cancer cells from growing.

5. Targeted Therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells.

Drugs for Thyroid Cancer approved by The Food And Drug Administration (FDA)

• Cabozantinib-S-Malate
• Caprelsa (Vandetanib)
• Cometriq (Cabozantinib-S-Malate)
• Doxorubicin Hydrochloride
• Lenvatinib Mesylate
• Lenvima (Lenvatinib Mesylate)
• Nexavar (Sorafenib Tosylate)
• Sorafenib Tosylate
• Vandetanib