Symptoms
- No symptoms
- Lump in thyroid
- Enlarged thyroid
- Hoarseness
- Difficulty swallowing
- Shortness of breath
- High-pitched breathing
Description
Thyroid cancer starts in the thyroid gland causing cells to experience abnormal growth.
There are many different types of thyroid cancer. The different types are defined
by which thyroid cell the cancer affects. The most common is differentiated thyroid
cancer. There are two types: papillary carcinoma and follicular carcinoma. The other
types of thyroid cancer, such as medullary thyroid carcinoma and anaplastic thyroid
carcinoma, are rarer.
Papillary Carcinoma
This type of thyroid cancer accounts for around 90% of cases. Tumor growth is relatively
slow. The cancer responds well to treatment, and the cancer is rarely fatal. It
takes place in the lobes of the thyroid gland and can sometimes spread to the lymph
nodes.
Follicular Carcinoma
This type of differentiated thyroid cancer is the rarer of the two. It affects the
follicular cells of the thyroid, which are responsible for converting the iodine
of the blood to thyroid hormone. This hormone helps the body control how it uses
energy.
Causes
The cause of differentiated thyroid cancer is unknown. There are a certain number
of risk factors linked to disease development. Thyroid cancer risk factors are anything
that may influence the chances of a person getting thyroid cancer.
- Gender - Women have a higher chance of developing thyroid cancer than men.
- Age - Thyroid cancer is more common in the age groups of 40-50 years old in women and 60-70
years old in men.
- Ionizing radiation - Exposure to high dose radiation in adolescence and childhood is a well-established
risk factor for thyroid cancer. Exposure to radiation can happen during medical
treatment, and on a larger scale, during nuclear power plant accidents.
- Previous thyroid disease - Individuals who have had a benign (non-cancerous) thyroid tumor have an increased
risk of developing thyroid cancer.
- Family History - A family history of thyroid cancer increases the risk of developing the disease.
Treatment
There are a number of therapies for differentiated thyroid cancer. Treatment is guided
by the age of the patient and pre-existing medical conditions.
Surgery
This is a popular treatment for thyroid cancer. Depending on whether the cancer has
metastasized (spread from the primary site on the thyroid to other tissues), all
or part of the thyroid may be removed. A risk in this surgery includes damage to
the laryngeal nerve, which can result in the patient developing breathing problems.
Radioactive Iodine Treatment (RIT)
During RIT, large doses of radioactive iodine are given. As the thyroid absorbs iodine
from the blood, the radioactive iodine kills cancer cells in the thyroid gland.
This treatment can be used alone or as a secondary treatment after surgery. Complications
include a buildup of fluid in the neck area, inflammation of the thyroid, and inflammation
of the salivary glands.
Thyroid Hormone Treatment
If the thyroid gland is removed, a person will need to take thyroid hormone replacement
drugs. These prevent hypothyroidism and reduce the risk of the thyroid cancer cells
returning. Levothyroxine (Synthroid*) is a commonly used thyroid hormone replacement
drug.
External Beam Radiation Therapy
Radiation is delivered to the cancerous thyroid cells, destroying and slowing cancer
growth. Typically, this type of treatment is used for the less common medullary
and anaplastic thyroid cancers. Complications can result from the radiation by destroying
healthy cells in addition to the targeted cancerous cells.