- [Instructor] Thyroid cancer is a disease that begins
in your thyroid gland.
Your thyroid gland is located over your larynx or voice box.
It wraps around your trachea or wind pipe.
Your thyroid produces two hormones called thyroid hormone
and calcitonin,
and secretes them directly into your bloodstream.
Inside your thyroid gland,
follicular cells make thyroid hormone.
Your body uses thyroid hormone to increase your energy
and raise your body temperature when necessary.
For example, these effects help offset
the heat your body loses when exposed to cold weather.
Parafollicular cells in your thyroid make calcitonin.
Calcitonin is thought to stimulate
the formation of new bone.
If you have thyroid cancer, it may be one of four types
depending on the type of thyroid cell
in which the cancer started
and the appearance of the cancer cells.
Papillary carcinoma is the most common thyroid cancer
and begins in follicular cells.
Follicular carcinoma accounts for one in 10 cases
and also begins in follicular cells.
Medullary carcinoma is less common
and starts in parafollicular cells.
Anaplastic thyroid carcinoma is a rare,
more dangerous form of thyroid cancer.
Thyroid cancer, like all cancers
is an unrestrained growth of cells
due to damaged genetic material in the cells nucleus.
A tumor forms as the cells begin to accumulate.
Over time, a lump forms in your thyroid
as the tumor enlarges.
You may feel a lump in your neck over the thyroid gland.
You may have neck or throat pain, hoarseness
and trouble swallowing
as the tumor grows around your trachea.
To treat thyroid cancer,
your doctor may recommend surgery
followed by thyroid hormone therapy,
radiation therapy or chemotherapy.
Surgery is the most common treatment
for all types of thyroid cancer.
If you have surgery,
your doctor will usually remove your entire thyroid gland.
Your doctor may remove nearby lymph nodes as well.
After surgery, your doctor may recommend
thyroid hormone therapy.
Without your thyroid,
your body will have low levels of thyroid hormone.
This condition stimulates the pituitary gland in your brain
to release thyroid stimulating hormone.
Increased levels of thyroid stimulating hormone
cause any remaining thyroid cancer cells to grow faster.
If you take thyroid hormone,
it will reduce the amount of thyroid stimulating hormone
circulating in your body,
which will prevent the cancer cells from growing.
If you have anaplastic thyroid cancer
and have already had surgery,
your doctor may recommend radiation therapy
such as external beam radiation therapy.
Radiation damages
and kills any remaining thyroid cancer cells.
After surgery, your doctor may give you a pill
containing another type of radiation therapy
called radioactive iodine.
Any remaining thyroid cancer cells
absorb the radioactive iodine, which kills them.
Your doctor may recommend chemotherapy
for anaplastic thyroid cancer
that does not respond to surgery or radiation
and has spread.
Chemotherapy uses drugs
to stop the progression of cancer
by either killing the cancer cells
or preventing further growth.