Thyroid Cancer Essay, Research Paper
Cancer of the thyroid may be one of the less frequently occurring forms of
cancer, but it is the most common malignancy of the endocrine system. Each year,
more than 1,100 Americans are diagnosed with thyroid cancer and most of them can
expect to live a normal life span (Health Conn. html). The overall incidence of
being diagnosed with thyroid cancer is about 1 out of every 1,000 people (Health
Answers. html). As with other thyroid conditions, more than twice as many women
as men develop thyroid cancer. Most men and women who are diagnosed with this
type of cancer are between the ages of twenty-five and sixty-five years (Health
Conn. html). General Description Cancer is a disease in which abnormal cells in
some organ or tissue go out of control, growing and increasing in number. Normal
cells reproduce themselves throughout life, but in an orderly and controlled
manner. When normal cell growth occurs, worn out tissues are replaced and wounds
are healed. But when cells grow out of control, they form a mass called a tumor.
Some tumors grow and enlarge only at the site where they began. These types of
tumors are referred to as benign tumors. Other tumors not only enlarge locally,
but they also have the potential to invade and destroy the normal tissues around
them and to spread to other regions of the body. These types of tumors are
called malignant tumors or cancer.(Mediconsult html) Malignant tumors of the
thyroid gland tend to develop gradually and remain localized. The tumors usually
appear as nodules or lumps of tissue growing on or inside the gland itself. Most
lumps on the neck, however, are usually caused by thyroid conditions such as
goiters.(Mediconsult html) There are four main types of thyroid cancers:
papillary, follicular, medullary, and anaplastic (also referred to as
undifferentiated) (Graylab html). These tumors are identified by the type of
cells seen under the microscope. Papillary thyroid tumors occur most often. This
type of thyroid cancer develops on one or both sides of the gland and remains
confined for several years. Follicular tumors, on the other hand, grow only on
one side of the gland. Medullary thyroid tumors are usually uncommon, and like
papillary tumors, they grow on one or both sides of the gland . Anaplastic
tumors, though extremely rare, develop on either side of the thyroid gland and
spread rapidly to other parts of the body (Thyroid Cancer Overview). Causes The
only known risk for thyroid cancer in some people is external radiation to the
head and neck areas. From the early 1920’s to the late 1950’s, thousands of
children received x-ray treatments to the head and neck areas (Health Conn.
html).Back then x-ray therapy was used to treat inflammation of the tonsils and
adenoids, ringworm of the scalp, ear infections, acne, and other non-cancerous
conditions (Health Answers html). At the time physicians had no indications that
external radiation treatment could lead to thyroid cancer. Several years later,
thyroid tumors began to appear in people who had received this type of radiation
therapy. Fortunately most of the tumors were slow-growing and not malignant
(Health Conn. html).Other risks factors for thyroid cancer include patients with
a family history of thyroid cancer and patients who experience chronic goiters
(National Cancer Institute html). Symptoms Malignant thyroid tumors may develop
without any detection for many years after its original formation. Aside from a
slightly enlarged thyroid gland or lump located in the neck region, there are no
early signs or symptoms that indicate this type of cancer. If the malignant
tumor is left undetected and untreated, the later stages of thyroid cancer might
cause more obvious symptoms (UPHS Health html). Such symptoms could possibly be
hoarseness or a slight change in the voice due to pressure from the tumor on the
nerve connected to the voice box or, difficultly in swallowing or breathing due
to a tumor obstructing the esophagus or windpipe (Thyroid Cancer Overview html).
Other signs of thyroid cancer are chronic coughing or coughing accompanied by
bleeding, or diarrhea or constipation (American Cancer Clinic html). Diagnosis
The diagnosis of cancer is terrifying for most patients because it has become
associated with extreme pain and suffering (Brochlure.1 html). But what the
patients do not realize is that there are a number of tests that can be
performed to determine the existence of a malignant or benign thyroid tumor, and
most of these tests cause little pain or disability (Mediconsult html). Most
cases of thyroid cancer are found during a routine physical examination. If the
gland appears to be enlarged, the physician may order further tests to diagnose
or rule out cancer (CRHA html). These tests include: * Thyroid scan- a patient
is given radioactive iodine to drink. After the iodine has been absorbed by the
thyroid, the patient must lie on his or her back with the neck region positioned
under a scanner. The information received by the scanner is then sent to a
computer that displays a 2-dimensional image of the thyroid and any tumors that
have absorbed the iodine. There is no discomfort felt during this testing, and
slight nausea due to the iodine mixture is the only reported reaction to this
testing. A thyroid scan is about 80 to 85% accurate, and it costs an estimated
$50- $120, plus any hospital stay and extra computer costs. (Health Answers
html) * Thyroid ultrasound- The ultrasound uses high-frequency sound waves that
are emitted and received by a transducer (a hand-held instrument) that is passed
over the neck region. The sound waves penetrate the body, and by electronic
readings, the sound waves are arranged on a computer screen into a picture image
of the thyroid gland and any tumors. A thyroid ultrascan is completely harmless,
and it is about 80 to 97% accurate. The costs range anywhere from $75-$100.
(Health Answers html) * Thyroid excisional biopsy- the test is done in a
hospital operating room under a general anesthesia. A sedative is usually given
by an injection about one hour before the procedure. An intravenous line is
placed in a vein in the arm. Throughout the procedure, the patient is given a
mixture of anesthetic gas and oxygen through a hollow tube t
through the mouth and into the trachea. A small incision is made in the neck,
and either side of the thyroid or the entire lump is removed. The sample is sent
to a laboratory to be examined. If thyroid cancer is detected, the thyroid is
removed. The incision is then stitched up. A patient who undergoes a thyroid
excisional biopsy will experience drowsiness, a mild sore throat, and some
discomfort from the incision. The test is highly accurate and costs any where
from $300 to $1,000. (Health Answers html) * Laryngoscopy- it is the examination
of the interior of the larynx with either the aid of a small mirror held against
the back of the palate or a flexible viewing tube called a laryngoscope. This
type of testing may cause a sore or hoarse throat. It is 50 to 75% accurate and
costs around $65. (Health Answers html) Cancer development Once the cancer of
the thyroid is diagnosed, more tests can be done to find out if cancer cells
have spread to other parts of the body. This is called staging. A physician
needs to determine which stage the cancer is in order to plan the proper
treatment (American Cancer Clinic html). There are four main stages in each of
the types of thyroid cancer except for anaplastic (undifferentiated) cancer. In
the stage I of papillary thyroid cancer, the cancer is located only in the
thyroid and may be found in one or both of the lobes. In stage II if the
patients are younger than 45 years of age, the cancer has spread beyond the
thyroid. But if the patient is older than 45 years of age, the cancer is only in
the thyroid and is larger than 1 centimeter. In stage III, the cancer is usually
found in patients older than 45 years of age and has spread outside of the
thyroid or has spread to the lymph nodes but not outside of the neck. In stage
IV, the cancer is again usually found in patients over the age of 45. It most
likely has spread to other parts of the body such as the lungs or bones. (Graylab
hmtl) In stage I of follicular thyroid cancer, the cancer is only found in the
thyroid gland on one of the lobes. In stage II if the patient is younger than 45
years of age, the cancer has spread beyond the thyroid to the lymph nodes. If
the patient is older than 45 years of age, the cancer is only in the thyroid and
is larger than 1.5 centimeters. In stage III, the cancer is usually found in
patients older than 45 and has spread to beyond the thyroid into other areas of
the neck and maybe outside of the neck. Stage IV of follicle thyroid cancer is
very similar to stage IV of papillary thyroid cancer in that the cancer has
probably spread to the lungs and various bones. (Graylab html) Medullary thyroid
cancer is quite uncommon. In stage I, the is located in one or both of the
thyroid glands and is about 1 centimeter in size, but throughout the last three
stages of medullary thyroid cancer, the tumor grows by 1-4 centimeters and
continuously spreads to other parts of the body. (Graylab html) There is no
staging system for anaplastic cancer of the thyroid. This cancer is located in
either of the lobes and spreads faster than any of the other types. (Graylab
html) Treatment There are basically four different types of treatments used on
patients with cancer of the thyroid: surgery, radiation therapy, hormone
therapy, and chemotherapy (National Cancer Institute html). Each treatments are
widely used in fight against thyroid cancer, but not all yield the same results.
Surgery the most common treatment for cancer of the thyroid. A physician can
remove the cancer by using one or several operations. A lobectomy removes only
the side of the thyroid where the cancer is found. A near-total thyroidectomy
removes all of the thyroid except for a small portion. A total thyroidectomy
removes the entire thyroid, and a lymph node dissection removes lymph nodes in
the neck that contain cancer. Complications of surgery include: hemorrhage,
damage to the parathyroid glands, and temporary or permanent damage to the vocal
chords. Any type of surgery for thyroid cancer is followed up by a series of
oral doses of radioactive iodine. The concentrations of iodine destroy any
residual thyroid tissue or tumor. Radiation therapy uses high-energy x-rays to
kill cancer cells and shrink tumors. Radiation for cancer of the thyroid may
come from a machine outside of the body (external radiation therapy) or from
drinking a liquid that contains radioactive iodine. Because the thyroid absorbs
the iodine, the radioactive iodine collects in any thyroid tissue remaining in
the body and kills the cancer cells. Side effects of radiation therapy include:
edema, increased skin pigment, skin itching, desquamation( shedding of outer
layer of skin), nausea, vomiting, hair loss, and possible fetal damage in women.
Hormone therapy uses hormones to stop cancer cells from growing. In treating
cancer of the thyroid, hormones can be used to stop the body from making other
hormones that might make cancer cells grow. The hormones are usually ingested
orally in the form of a pill. There are generally no side effects to hormone
therapy other than slight nausea, vomiting, and diarrhea. Chemotherapy uses
drugs to kill cancer cells. Chemotherapy may be taken by a pill, or it may be
put into the body by a needle in the vein or muscle. Chemotherapy is called a
systemic treatment because the drug enters the blood stream, travels through the
body, and can kill the cancer cells outside of the thyroid. Chemotherapy causes
similar side effects to those of radiation therapy. Prognosis Fortunately in
most cases, people with the cancer of the thyroid are usually treated
successfully. Papillary cancer of the thyroid is not associated with a high
degree of progression so many people maintain a normal life expectancy ,if
diagnosis is made early. Follicular cancer of the thyroid is often fast growing
and may invade other tissues, but the probable outcome is still good. The
outcome of medullary cancer of the thyroid varies. Women under the age of 40
have a better chance of a good outcome. The number of people who live at least
10 years after diagnosis is 46%.Anaplastic cancer of the thyroid has the worst
prognosis. The expected life span of anyone diagnosed with this type of thyroid
cancer is anywhere from 6 months to 3 years.