Thyroid
Cancer
The thyroid gland is located below the larynx
in the throat. It is butterfly-shaped and can be felt when
swallowing. The thyroid produces hormones: triiodothyronine
(T3) and thyroxine (T4). Thyroid cells are the only ones in
the body to absorb iodine. Iodine combines with tyrosine to
make T4. The thyroid hormones aid in the metabolism of all
cells in the body. They help regulate heart rate, blood
pressure, body temperature, and weight, among other important body
functions. According to the American Cancer Society,
about 62,000 adults in the USA are diagnosed with thyroid cancer
each year. It is the fifth most common cancer in women, often
those aged between 40 and 50. It is also the most rapidly
increasing cancer in the USA, and can occur in women who are 20
years old.
Thyroid cancer doesn’t really show any early
symptoms. As it begins to grow, it may cause:
- a lump that can be felt in the throat with or
without pain;
- hoarseness, difficulty in swallowing;
- swollen glands in the neck;
- difficulty breathing, and a constant cough
which is not due to a cold.
There are several factors that increase the
risk of thyroid cancer. These are:
- Being female: it is three times more often
seen in women. In men, it more often occurs between the ages
of 60 and 70.
- Exposure to high levels of radiation, such as
radiation treatments to the head or neck for other cancers, or
fallout from a nuclear power plant or nuclear weapons
testing. According to Mayo Clinic, “if you live within 10
miles of a nuclear power plant, you may be eligible to receive a
medication that blocks the effects of radiation on the
thyroid. If an emergency should occur, taking the tablets
could help prevent thyroid cancer. Contact the state or local
emergency management department for more information.”
- Some genetic syndromes such as certain types
multiple endocrine-related cancers.
- Lack of iodine in the diet, common in
countries where iodine is not added to salt or other foods.
There are four main types of thyroid
cancer:
- Papillary: the most common type which grows
slowly and is usually found in only one of the two lobes. It is
very curable if found early and in those under 45 years old.
The tumor looks very like normal thyroid tissue under a microscope.
This is called differentiated thyroid cancer.
- Follicular: grows slowly, and is more
differentiated and less common than papillary. It is also
very curable when found early and in people younger than age
45. Papillary and follicular types make up about 90 per
cent of all thyroid cancers.
- Medullary: genetic origin and does not look
like normal thyroid tissue under a microscope. It makes up
about five per cent of all thyroid cancers.
- Anaplastic: rare, fast growing, and more
difficult to treat since it grows so quickly. It makes up
about two per cent of thyroid cancer.
Thyroid cancer is often found during routine
checks or testing for other problems. A thorough medical and
family history will be obtained. A biopsy will be done using
ultrasound, and if the lab results are malignant, surgery will be
performed to remove all or part of the thyroid and, sometimes,
enlarged lymph nodes from the neck. After the thyroid is
removed, medication (thyroid hormone) will be given for the rest of
the individual’s life. This replaces the hormones that the
thyroid normally produces, and it prevents the pituitary gland from
producing thyroid-stimulating hormone (THS), that could cause any
remaining thyroid cancer cells to grow. Other treatment
options include radioactive iodine, radiation therapy,
chemotherapy, injecting alcohol into small cancers that are
difficult to get to during surgery, and the use of certain
medications, especially in advanced thyroid cancer.
Pat Crouch, RN, BSN
Faith Community Nurse, St. John Lutheran
church, Country Club Hills, Illinois, USA