2. Thyroid cancer begins in the thyroid gland. This gland is part of the endocrine system,
which regulates hormones in the body. It absorbs iodine from the bloodstream to
produce thyroid hormones to regulate the body's metabolism.
The thyroid gland is located in the front of the neck, just below the larynx (voice box). A
normal thyroid gland has 2 lobes, 1 on each side of the windpipe. The lobes are joined
by a narrow strip of tissue called the isthmus.
A healthy thyroid gland is barely palpable, which means it is hard to find by touch. A
swollen or enlarged thyroid is called a goiter. Most often, a goiter is not caused by
cancer. Worldwide, goiters are most often caused by a lack of iodine in the diet. In the
United States, most people get enough iodine from salt, so the most common cause of
goiters is too much or too little thyroid hormone. Sometimes, the cause of a thyroid
goiter is cancer. If a tumor develops in the thyroid, it is felt as a lump in the neck.
3. Thyroid cancer starts when healthy cells in the thyroid change and grow out of control,
forming a mass called a tumor. The thyroid gland contains 2 types of cells:
• Follicular cells. These cells are responsible for the production of thyroid hormone.
Thyroid hormone is needed to live. The hormone controls the basic metabolism of the
body.
• C cells. These special cells of the thyroid make calcitonin, a hormone that participates
in calcium metabolism.
A tumor can be cancerous or benign. A cancerous tumor is malignant, meaning it can grow
and spread to other parts of the body. A benign tumor means the tumor can grow but will
not spread. Thyroid tumors can also be called nodules, and about 90% of all thyroid
nodules are benign.
4. There are 5 main types of thyroid cancer:
• Papillary thyroid cancer. Papillary thyroid cancer develops from
follicular cells and usually grow slowly. It is the most common type of
thyroid cancer. It is usually found in 1 lobe. About 10% to 20% of
papillary thyroid cancer appears in both lobes. It is a differentiated
thyroid cancer, meaning that the tumor looks similar to normal
thyroid tissue under a microscope. Papillary thyroid cancer can often
spread to lymph nodes but it is generally treatable with a good
prognosis.
5. • Follicular thyroid cancer. Follicular thyroid cancer also develops from
follicular cells and usually grows slowly. Follicular thyroid cancer is also
a differentiated thyroid cancer, but it is far less common than papillary
thyroid cancer. Follicular thyroid cancer rarely spreads to lymph nodes.
Follicular thyroid cancer and papillary thyroid cancer are the most
common differentiated thyroid cancers. They are very often curable,
especially when found early and in people younger than 50. Together,
follicular and papillary thyroid cancers make up about 95% of all thyroid
cancer.
• Hurthle cell cancer. Hurthle cell cancer, also called Hurthle cell
carcinoma, is cancer that is arises from a certain type of follicular cell.
Hurthle cell cancers are much more likely to spread to lymph nodes
than other follicular thyroid cancers.
6. • Medullary thyroid cancer (MTC). MTC develops in the C cells and is
sometimes the result of a genetic syndrome called multiple endocrine
neoplasia type 2 (MEN2). This tumor has very little, if any, similarity to
normal thyroid tissue. MTC can often be controlled if it is diagnosed and
treated before it spreads to other parts of the body. MTC accounts for about
3% of all thyroid cancers. About 25% of all MTC is familial. This means that
family members of the patient will have a possibility of a similar diagnosis.
• Anaplastic thyroid cancer. This type is rare, accounting for about 1% of
thyroid cancer. It is a fast-growing, poorly differentiated thyroid cancer that
may start from differentiated thyroid cancer or a benign thyroid tumor.
Anaplastic thyroid cancer can be subtyped into giant cell classifications.
Because this type of thyroid cancer grows so quickly, it is more difficult to
treat successfully.
7. - lodine: iodine-deficient diets may lead to increase
the TSH level and considered goitrogenic
- Thyroiditis: (Hashimoto's Disease) may develop into a form of
cancer called lymphoma
- External Radiation
- Increased Age ( 20 to 55 years)
- Nuclear power plant accident
- Food source contaminated with radioactivity
- Radioactive iodine concentrated in the thyroid gland
8. - A lump in the neck, near the adams apple
sometimes growing quickly
- Swelling in the neck
- Pain in the front of the neck, sometimes going up to the ears
- Hoarseness or other voice changes that do not go away
- Trouble swallowing ( Dysphagia)
- Trouble breathing ( Dyspnea)
- A constant cough that is not due to a cold
9. • Physical examination. Neck, thyroid gland, throat, and lymph nodes for unusual growths or
swelling.
• Blood tests. This includes tests called tumor marker tests.
• may include:
◦ Thyroid hormone levels. For the current levels of the thyroid hormones triiodothyronine (T3)
and thyroxine (T4) in the body.
◦ Thyroid-stimulating hormone (TSH). To measures the level of TSH.
◦ Medullary type-specific tests. For high calcitonin and carcinoembryonic antigen (CEA) levels
also the presence of RET proto-oncogenes.
◦ Ultrasound. An ultrasound tells us about the size of the thyroid gland and specific information
about any nodules, including whether a nodule is solid or a fluid-filled sac called a cyst.
• Biopsy. A biopsy is the removal of a small amount of tissue and examined to make a definite
diagnosis. A biopsy for thyroid nodules will be done in 1 of 2 ways:
◦ Fine needle aspiration.
◦ Surgical biopsy. When the needle aspiration biopsy is not clear.
◦ Molecular testing of the nodule sample. Genetic analysis of your thyroid nodule may allow you
to understand the risk of the thyroid nodule being cancerous.
• Radionuclide scanning. This test may also be called a whole-body scan. This scan will either be
done using a very small, harmless amount of radioactive iodine, called a tracer.
• X-ray.
• Computed tomography (CT or CAT) scan. To see the inside of the body using x-rays taken from
different angles.
• Positron emission tomography (PET) or PET-CT scan. A PET scan is a way to create pictures of
organs and tissues inside the body.
13. Surgery
Surgery is the removal of the tumor and some surrounding healthy tissue during an operation,
called a margin. It is the main treatment for most people with thyroid cancer. Depending on the
size of the thyroid nodule, common surgical options include:
• Lobectomy. This surgery removes the lobe of the thyroid gland with the cancerous
nodule.
• Near-total thyroidectomy. Also called subtotal thyroidectomy, this is surgery to removes
most of the thyroid gland. A small amount of thyroid tissue remains.
• Total thyroidectomy. This surgery removes the entire thyroid gland.
Hormone treatment
Patients who are treated with surgery usually require thyroid hormone therapy. In addition to
replacing the hormone that is needed by the body, the thyroid hormone medication may slow
down the growth of any remaining differentiated cancer cells.
Radioactive iodine ( radio-iodine ) therapy
The thyroid absorbs almost all iodine that enters a body. Therefore, a type of radiation therapy
called radioactive iodine (also called I-131 or RAI) can find and destroy thyroid cells not
removed by surgery and those that have spread beyond the thyroid.
14. External-beam radiation therapy
External-beam radiation is another type of radiation therapy in which high-energy x-rays
are given from a machine outside the body to destroy cancer cells
Therapies using medication
The treatment plan my include medications to destroy cancer cells. Medication may
be given through the bloodstream to reach cancer cells throughout the body. When a
drug is given this way, it is called systemic therapy.
The types of medications used for thyroid cancer include:
Chemotherapy
Chemotherapy is the use of drugs to destroy cancer cells, usually by keeping the cancer
cells from growing, dividing, and making more cells. In this the patient may receive 1 drug
at a time or a combination of different drugs at the same time.
Targeted therapy
Targeted therapy is a treatment that targets the cancer’s specific genes, proteins, or the
tissue environment that contributes to cancer growth and survival. This type of treatment
blocks the growth and spread of cancer cells and limits damage to normal cells.
