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THYROID CANCER
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THYROID CANCER
What Is Thyroid Cancer?
The thyroid, like other body organs, goes through a rapid development stage as we grow from infancy to adulthood. The thyroid cells grow and produce their hormones in a tightly controlled manner. In the adult, thyroid cells only divide to replace those lost through old age or injury. Thyroid cancer starts In just one cell. Something goes awry in the internal workings of this cell; in it's "genes". The genes contain the genetic information that controls the cell; they may be influenced by outside hormones. With specific types of gene damage, the cell starts dividing out of control, forming a tumor. A tumor simply means a swelling, and is not necessarily cancer. A benign tumor only grows in it's local area (although it can become very large); it is not cancer. However, a malignant tumor can spread ("metastasize") to other body areas and Is cancerous. It is this ability for malignant tumors to spread to other vital organs, and disturb their functioning, that makes cancer dangerous.
How Common Is Thyroid Cancer?
Each year in the U.S.A. there are 1 5,600 new cases of thyroid cancer causing 1,200 deaths. Thyroid cancer accounts for just 1.5% of new cancers in the U.S.A. Women are affected more than men three cases to two. The risk increases with age, the average patient is 50 years old. Thyroid cancer is rare in people younger than 30. Thyroid cancer is more common in people of Asian extraction,and the number of cases has Increased worldwide over the past decade.
What Causes or Increases the Risk for Thyroid Cancer?
Like any cancer, why any one person develops the disease and another does not remains unknown. However, several factors have been noted to Increase risk for thyroid cancer by studying groups of patients; these are called "risk factors":
1) Goiter simply means an enlarged thyroid gland. It can be either generally big or just have separate areas of enlargement (nodules). It the pituitary gland in the brain makes too much TSH, then the thyroid will enlarge. Goiters can be present at birth or develop later in life. Iodine is necessary for the the thyroid to make it's
hormones and with iodine insuff iciencency, a goiter will develop as the brain tries to stimulate the thyroid to make it's crucial hormones. In general, having a goiter increases the risk of thyroid cancer. In animals, thyroid cancer has been produced by severe iodine restriction, giving lots of TSH, and "goiterogen" foods (such as cabbage and rapeseed oil) that stimulate goiter.
2) Nodules of the thyroid are simply "bumps" or uneven areas of enlargement. It there are many nodules, the thyroid may enlarge ("multinodular goiter"). About 4% of the American population has thyroid nodules. Clinically speaking, a lump is called a "nodule" If it is more than 1 cm. (1/2") in size. While any growing nodule in the thyroid is suspicious for cancer, most are benign. Nodules may be either "hot" (function to produce thyroid hormone), "cold" (don't function to make hormones) or "warm" (make a little hormone, but not much). Over 90%
of thyroid nodules are "OK. Even though a "cold" nodule Is more likely to be cancerous than a "hof'one, only 1 0% of cold nodules are cancerous. A single nodule is more likely to be cancer than multiple nodules, Larger nodules (over 5 cm. or -2 inches) are more likely to be cancerous than small ones. A "cold" nodule in a male under 30 years old is particularly worrisome for cancer. Nevertheless, all suspicious nodules should be checked for cancer!
3) Radiation Exposure is a risk factor for developing thyroid cancer. Radiation causes changes in the genes of the thyroid cells, and increases the chance for nodules. Young people (under 30 years old) who get radiation to the neck area are at highest risk. Some young Japanese who survived the atomic bomb later developed it. Radiation is linked to slow growing thyroid cancer that often takes 10 - 30 years after the exposure to become apparent. Radioactive lodine-1 31 used for to destroy (ablate) thyroid tissue for treatment of hyperthyroldism has not been linked to later development of cancer.
4) Family History of thyroid cancer in first degree (close) relatives or rare familial
5) Genetic diseases like "multiple endocrine neoplasia" ("MEN" syndrome) raises thyroid cancer risk. Twenty percent of thyroid cancer patients have a family history of goiter. Goiter was much more common in the "Goiter Belt" (Midwest) of the U.S.A. prior to salt being "iodized".
Chronic Infections or Inflammation of the thyroid, as from Hashimoto's Thyrolditis (an "auto-immune" disease where the body's own Immune system turns agains the thyroid tissue) increase cell division in the thyroid. The more often cells divide, the more likely a change ("mutation") will arise in its genes, and certain mutations presage cancer. Anything that irritates the thyroid gland over time will increase cancer risk.
***Alcohol and Tobacco use havn't been linked to getting thyroid cancer.
What are the Signs and Symptoms of Thyroid Cancer?
The way a patient appears when they first come to medical attention is called their "presentation". This is described by "signs" which are things that can be measured (such as the size of a nodule or fever), and "symptoms" which are things the patient feels (such as pain or decreased appetite). A high "suspicion Index" is the first step.
Early thyroid cancer usually has no symptoms, it is just a small lump in the thyroid.
As the cancer grows, it may produce the following symptoms:
1) Neck Mass-- The patient (or their doctor) may notice a mass or goiter in the neck. doctors should feel ("palpate") for thyroid nodules as part of a complete physical examination. One-third of thyroid cancers are discoved from a routine exam of the neck. Eventually 75% of theyrold cancer patients will develop a noticeable swelling In the neck.
2) Hoarseness-- If the cancer invades a nerve controlling the voicebox, called the "recurrent laryngeal nerve", hoarseness of voice will result. About 15% of patients with thyroid cancer have hoarseness.
3) Neck Pain-- A pain or pressure sensation in the low neck Is found in 10% of patients due to the cancer invading nerves of the neck.
4) Swallowing Difficulty-- This "dysphagis" is found in 15% of patients and is
due to a growing tumor pressing upon the esophagus (foodpipe). Actual pain on swallowing ("odynophagia") Is a later sign of deep nerve invasion.
5) Breathing Difficulty-- This "dypnea" is found In 10% of patients and is due to
growing tumor pressing upon the trachea (windpipe).
6) Swollen Glands-- This Illymphadenopathyll can represent spread of the
cancer to the lymph gland in the neck. These lymph glands are part of the immune system that filters blood serum and destroys germs ("pathogens") They are normally bean sized, but can swell up to large masses If invaded by infection or cancer (or both). Neck lymph gland swelling may be the first sign of thyroid cancer, but is much more commonly due to benign conditions.
7) Signs of Distant Spread-- If the cancer has spread out of it's local area, it
may "seed" to bone, lung, liver, brain or virtually any other location in the body, causing symptoms there from a "metastatsis" (distant cancer spread).
The thyroid is a gland in the low neck, in front of the windpipe, that controls the body's metabolic rate. It produces crucial hormones that speed up or slow down the speed at which the human machine operates. Additionally, it maintains blood calcium balance within a narrow range, this is critical to maintaining consciousness and moving our muscles. You can see that the thyroid gland is necessary for life.
It is critical to get the proper diagnosis and treatment for a thyroid cancer problem; this can literally make the difference between life and death. While some thyroid cancers act in a benign fashion, being rarely fatal, others are among the most aggressive cancers known! Understanding your options will give you the peace-of-mind knowing that you have done everything possible for a successful outcome for yourself or a loved one.
The Cancer Group's material explains, in plain English, the definition, types, frequency, symptoms, evaluation, historical and latest effective treatments for thyroid cancer. We describe surgery, radiation, and chemotherapy, and tell you their side-effects and results. While we don't promise a cure, we tell you everything you need to know to help make the right choices today to deal with a thyroid cancer problem.
