Already a member?
Sign in
Thyroid Cancer
General Description:
Thyroid cancer is an oddball among cancers, for several reasons.
Your thyroid is a small, butterfly-shaped gland that lies just above your collar bone at the front of your throat. Your thyroid produces hormones that regulate your body's metabolism, literally effecting every cell in your body. Too much thyroid hormone and you'll feel "wired and tired", too little, and you'll feel sluggish, both mentally and physically. Thyroid cancer can manifest by producing either one of these states.
The incidence of thyroid cancer is rising in the United States, but that is likely due to more diligence in detection. Every year, some 20,000 to 30,000 patients are diagnosed with thyroid cancer in the US. About three-quarters of thyroid cancer patients are women; thyroid cancer is rarely seen in children.
There are four main types of thyroid cancer: papillary or mixed papillary/follicular, which makes up 78% of cases, follicular, about 17%, medullary, 4%, and anaplastic, 1%. Variants of papillary and follicular cancers include tall cell, Hurthle cell, insular, and columnar. Papillary and follicular cancers are known as "well-differentiated" cancers, and treatment of these types yield excellent prognoses. Chief Justice William Rehnquist died of anaplastic thyroid cancer in 2004.
So, what makes thyroid cancer an oddball?
Causes & Risk Factors:
The most signficant acknowledged risk factor for thyroid cancer is radiation exposure. Radiation treatments to the head and neck area, or exposure to radiation as the result of a nuclear accident can cause thyroid cancer. The incidence of thyroid cancer near Chernobyl skyrocketed following the melt-down there. Dental x-rays have not been suspected of causing thyroid cancer.
A less significant risk factor is family history, but this link is strongest for medullary thyroid cancer cases.
There is anecdotal evidence that chemical exposure to perchlorate or excess flouride (in drinking water) can lead to hypothryoidism, but there is no evidence that these chemicals cause thyroid cancer. There is also no evidence linking hypothyroidism or hyperthyroidism to thyroid cancer.
Detection & Diagnosis:
A skilled practitioner can do a neck examination and detect the presence of thyroid nodules, but the mere presence of a nodule is not an indicator of cancer.
Thyroid ultrasound is often used to evaluate a thyroid with nodules. There are some structural changes that can indicate the presence of cancer, such as calcification and increased vascularization (a build up of blood vessels; cancer cells have voracious appetites and create their own blood supply to feed themselves.) But ultrasound alone is not sufficient to diagnose cancer, either.
Definitive diagnosis can only be made via biopsy. Typically, a suspect nodule will be the target for a fine needle aspiration biopsy (FNA), in which the doctor uses a needle to draw some material out of the nodule for analysis. FNAs are notoriously finicky; it all depends on which cells get sucked up the needle. In the case of a negative biopsy, "watchful waiting" with repeated ultrasounds after 3 or 6 months, and repeated biopsies, is a reasonable course of action since most thyroid cancer is non-aggressive. Changes in the gland or nodule can be easily monitored using a baseline ultrasound, which can make diagnosis easier.
Follicular thyroid cancer can only be diagnosed with tissue samples (following surgical removal of the thyroid gland), because the structure and order of the cells are destroyed when they are extracted during an FNA biopsy.
Prevention:
In the event of a nuclear accident, the risk of developing thyroid cancer can be reduced by taking iodine. The iodine will saturate the thyroid gland, preventing any radioactive iodine from being absorbed.
Prognosis:
There are several different methodologies for staging thyroid cancer. Generally, age is the most important factor; patients diagnosed at less than 45 years old rarely die of this disease. Another of thyroid cancer's oddities: metastases to the lymph nodes of the neck do not generally affect the prognosis.
For papillary and follicular thyroid cancers, the prognosis is generally excellent. In fact, all cancers of this type without distant metastases are classified Stage 1, and those with distant metastases are classified as Stage 2. The 20-year mortality rate for Stage 1 thyroid cancer is less than 2%, and about 12% for Stage 2.
Medullary and anaplastic cancers are more serious, with much less positive outcomes.
Symptoms:
Often thyroid cancer will not produce symptoms, but the most common symptoms are those that accompany thyroid nodules: a lump in the throat, difficulty swallowing, changes in voice.
Treatment Options:
For papillary and follicular thyroid cancers, treatment follows this regimen:
Living with Thyroid Cancer
There are many adjustments to be made after surgery. Typically, thyroid hormones are not given immediately after surgery to force the patient's Thyroid Stimulating Hormone, or TSH, to very high levels to "wake up" any remaining thyroid cells. This period is unaffectionately known as "hypo hell" among thyroid cancer patients, because it's like falling into a pit: it can take months to recover from this deep, systemic period of hypothyroidism.
Endocrinologists who treat thyroid cancer patients use nuclear scans, in which tracer doses of radioactive iodine are given, to monitor the progress of the disease, at various intervals after the original surgery. In the past, this has required thyroid hormone withdrawal, but now more and more treatment centers are using synthetic TSH, Thyrogen.
One of the most important tools doctors use in monitoring thyroid cancer patients is a simple blood test for the presence of thyroglobulin (Tg). Tg is produced only by thyroid and thyroid cancer cells. Tg levels are measured both while on thyroid hormone medication ("suppressed") and under stimulation (the high TSH state caused either by thyroid med withdrawal or Thyrogen injections.) The goal is to have an undetectable Tg under stimulation, which indicates that the patient is cancer-free.
Many thyroid cancer patients have difficulty adjusting to their medications. TSH (thyroid stimulating hormone) is typically between 1 and 2 for people with normally functioning thyroid glands, but thyroid cancer patients must keep their TSH at or below 0.10 to keep any cancer activity suppressed. Technically, all such thyroid cancer patients are hyperthyroid. Many patients struggle to feel well on such high doses of medication, but with tweaks and adjustments, most find a livable dose.
For More Information
ThyCa: Thyroid Cancer Survivor's Association
EndocrineWeb's Thyroid Cancer page
Thyrogen Patient Information
Yahoo! Thyroid Cancer Support Group
Thyroid cancer is an oddball among cancers, for several reasons.
Your thyroid is a small, butterfly-shaped gland that lies just above your collar bone at the front of your throat. Your thyroid produces hormones that regulate your body's metabolism, literally effecting every cell in your body. Too much thyroid hormone and you'll feel "wired and tired", too little, and you'll feel sluggish, both mentally and physically. Thyroid cancer can manifest by producing either one of these states.
The incidence of thyroid cancer is rising in the United States, but that is likely due to more diligence in detection. Every year, some 20,000 to 30,000 patients are diagnosed with thyroid cancer in the US. About three-quarters of thyroid cancer patients are women; thyroid cancer is rarely seen in children.
There are four main types of thyroid cancer: papillary or mixed papillary/follicular, which makes up 78% of cases, follicular, about 17%, medullary, 4%, and anaplastic, 1%. Variants of papillary and follicular cancers include tall cell, Hurthle cell, insular, and columnar. Papillary and follicular cancers are known as "well-differentiated" cancers, and treatment of these types yield excellent prognoses. Chief Justice William Rehnquist died of anaplastic thyroid cancer in 2004.
So, what makes thyroid cancer an oddball?
- Thyroid cancer starts in thyroid nodules. ("Nodule" is just a fancy term for "lump.") Thyroid nodules are extremely common, and the overwhelming majority of them -- more than 95% -- are benign. So, having a thyroid nodule -- a lump on your thyroid -- is not a good indicator of whether or not you have thyroid cancer.
- The vast majority of thyroid cancers are slow-growing, so early detection is not as crucial as it is with other cancers.
- Thyroid cancer is typically managed by an endocrinologist, not an oncologist. With so (relatively) few cases each year, oncologists typically can't be bothered.
- Chemotherapy for thyroid cancer patients is completely unlike chemotherapy for other cancers. Treatment almost always involves surgical removal of the thyroid gland, leading to the need to take replacement thyroid hormones every day. Those hormones do double-duty and suppress further cancer growth.
- Most papillary and follicular cancers can be "cured." As noted above, these are "well-differentiated" cancers. They retain the major unique characteristic of healthy thyroid cells: the ability to absorb iodine. No other cells in the body can take in iodine, so that means that radioactive iodine can be used to detect and destroy thyroid cancer.
Causes & Risk Factors:
The most signficant acknowledged risk factor for thyroid cancer is radiation exposure. Radiation treatments to the head and neck area, or exposure to radiation as the result of a nuclear accident can cause thyroid cancer. The incidence of thyroid cancer near Chernobyl skyrocketed following the melt-down there. Dental x-rays have not been suspected of causing thyroid cancer.
A less significant risk factor is family history, but this link is strongest for medullary thyroid cancer cases.
There is anecdotal evidence that chemical exposure to perchlorate or excess flouride (in drinking water) can lead to hypothryoidism, but there is no evidence that these chemicals cause thyroid cancer. There is also no evidence linking hypothyroidism or hyperthyroidism to thyroid cancer.
Detection & Diagnosis:
A skilled practitioner can do a neck examination and detect the presence of thyroid nodules, but the mere presence of a nodule is not an indicator of cancer.
Thyroid ultrasound is often used to evaluate a thyroid with nodules. There are some structural changes that can indicate the presence of cancer, such as calcification and increased vascularization (a build up of blood vessels; cancer cells have voracious appetites and create their own blood supply to feed themselves.) But ultrasound alone is not sufficient to diagnose cancer, either.
Definitive diagnosis can only be made via biopsy. Typically, a suspect nodule will be the target for a fine needle aspiration biopsy (FNA), in which the doctor uses a needle to draw some material out of the nodule for analysis. FNAs are notoriously finicky; it all depends on which cells get sucked up the needle. In the case of a negative biopsy, "watchful waiting" with repeated ultrasounds after 3 or 6 months, and repeated biopsies, is a reasonable course of action since most thyroid cancer is non-aggressive. Changes in the gland or nodule can be easily monitored using a baseline ultrasound, which can make diagnosis easier.
Follicular thyroid cancer can only be diagnosed with tissue samples (following surgical removal of the thyroid gland), because the structure and order of the cells are destroyed when they are extracted during an FNA biopsy.
Prevention:
In the event of a nuclear accident, the risk of developing thyroid cancer can be reduced by taking iodine. The iodine will saturate the thyroid gland, preventing any radioactive iodine from being absorbed.
Prognosis:
There are several different methodologies for staging thyroid cancer. Generally, age is the most important factor; patients diagnosed at less than 45 years old rarely die of this disease. Another of thyroid cancer's oddities: metastases to the lymph nodes of the neck do not generally affect the prognosis.
For papillary and follicular thyroid cancers, the prognosis is generally excellent. In fact, all cancers of this type without distant metastases are classified Stage 1, and those with distant metastases are classified as Stage 2. The 20-year mortality rate for Stage 1 thyroid cancer is less than 2%, and about 12% for Stage 2.
Medullary and anaplastic cancers are more serious, with much less positive outcomes.
Symptoms:
Often thyroid cancer will not produce symptoms, but the most common symptoms are those that accompany thyroid nodules: a lump in the throat, difficulty swallowing, changes in voice.
Treatment Options:
For papillary and follicular thyroid cancers, treatment follows this regimen:
- Surgical removal of the affected portion of the thyroid gland. There is some controversy as to whether or not the entire gland needs to be removed if the cancer is well-encapsulated within one lobe, but generally, in the presence of cancer, the entire gland is removed.
- Treatment with radioactive iodine to destroy any remaining cancer. For this treatment to be effective, patients must follow a low iodine diet for two weeks prior to receiving the radioactive iodine. Patients must remain in isolation for at least 3 days after taking the dose.
- Thyroid hormone replacement at cancer-suppressive levels for the remainder of the patient's life.
Living with Thyroid Cancer
There are many adjustments to be made after surgery. Typically, thyroid hormones are not given immediately after surgery to force the patient's Thyroid Stimulating Hormone, or TSH, to very high levels to "wake up" any remaining thyroid cells. This period is unaffectionately known as "hypo hell" among thyroid cancer patients, because it's like falling into a pit: it can take months to recover from this deep, systemic period of hypothyroidism.
Endocrinologists who treat thyroid cancer patients use nuclear scans, in which tracer doses of radioactive iodine are given, to monitor the progress of the disease, at various intervals after the original surgery. In the past, this has required thyroid hormone withdrawal, but now more and more treatment centers are using synthetic TSH, Thyrogen.
One of the most important tools doctors use in monitoring thyroid cancer patients is a simple blood test for the presence of thyroglobulin (Tg). Tg is produced only by thyroid and thyroid cancer cells. Tg levels are measured both while on thyroid hormone medication ("suppressed") and under stimulation (the high TSH state caused either by thyroid med withdrawal or Thyrogen injections.) The goal is to have an undetectable Tg under stimulation, which indicates that the patient is cancer-free.
Many thyroid cancer patients have difficulty adjusting to their medications. TSH (thyroid stimulating hormone) is typically between 1 and 2 for people with normally functioning thyroid glands, but thyroid cancer patients must keep their TSH at or below 0.10 to keep any cancer activity suppressed. Technically, all such thyroid cancer patients are hyperthyroid. Many patients struggle to feel well on such high doses of medication, but with tweaks and adjustments, most find a livable dose.
For More Information
ThyCa: Thyroid Cancer Survivor's Association
EndocrineWeb's Thyroid Cancer page
Thyrogen Patient Information
Yahoo! Thyroid Cancer Support Group
|
Latest page update: made by
Anonymous
, Oct 3 2007, 8:06 AM EDT
(about this update
About This Update
Edited anonymously
view changes - complete history) |
|
Keyword tags:
Diagnosis
low iodine diet
nodule
nuclear scan
prognosis
radioactive iodine
thyroid
Thyroid cancer
thyroidectomy
treatment
More Info: links to this page
|
| Started By | Thread Subject | Replies | Last Post | |
|---|---|---|---|---|
| joan | planned pages | 1 | Mar 15 2006, 8:08 AM EST by Louise | |
|
Thread started: Mar 15 2006, 1:17 AM EST
Watch
As I have time, I plan to add pages for the Thyrogen protocol, Low Iodine Diet, nuclear scans, treatment with RadioActive Iodine, and others as they occur to me. Some sections on this main page may be moved to their own pages in the future.
|
||||
