Thyroid cancer is a disease that occurs when abnormal cells begin to grow in the thyroid gland. In other words thyroid cancer is a disease in which cancer (malignant) cells are found in the tissues of the thyroid gland.
The thyroid gland is a butterfly-shaped gland located at the base of the throat just below the Adam’s apple. It has two lobes, one on the right side and one on the left. The thyroid gland makes important hormones that help the body function normally.
Although the thyroid gland is small, it produces hormones that regulate every aspect of human metabolism. The thyroid gland makes hormones that regulate the way the body uses energy and help the body function normally.
Sometimes a person may develop one or more solid or fluid-filled lumps called nodules in the thyroid. Most of these are noncancerous (benign) and cause no symptoms. But a small percentage are cancerous (malignant), and serious complications are possible.
Thyroid cancer is a rare type of cancer. Most people who have it do very well, because thyroid cancer is usually found early and treated effectively.
The prognosis or the outcome of the disease is often excellent for a cancerous thyroid nodule. The most common types of thyroid cancer can often be completely removed with surgery. But the important first step is to know the symptoms and consult a doctor.
Certain factors may increase the risk of developing thyroid cancer.
- Thyroid cancer is most common among people between the ages of 25 and 65 years.
- Radiation or radiation treatments to the head and neck during infancy or childhood pose a greater risk in developing thyroid cancer. The cancer may occur as early as 5 years after exposure or may occur 20 or more years later.
- People who have had goiter (enlarged thyroid) or a family history of thyroid disease have an increased risk of developing thyroid cancer.
- Thyroid cancer is more common in women than in men.
- Asian people have an increased risk of developing thyroid cancer.
Cause of Thyroid Cancer
Healthy cells grow and divide in an orderly way. This process is controlled by DNA. DNA is the genetic material that contains the instructions for every chemical process in the body. When DNA is damaged or altered, changes occur in these instructions. One result is that cells may begin to grow out of control or abruptly without any requirement and eventually form a tumor which in turn is a mass of malignant cells.
Cause of thyroid cancer can be due to DNA damage from exposure to environmental contaminants such as radiation, from the aging process or, in medullary cancers, from genetic causes also such as:
Radiation: A person been exposed to radiation, has a greater risk of thyroid cancer, but it may not appear for decades after exposure.
Genetic causes: Genetic testing is controversial, especially when a disease can’t be prevented or successfully treated. But medullary thyroid cancer can be prevented by surgically removing the thyroid gland (thyroidectomy) before problems occur. Children at risk of MEN 2A may have this surgery around age 7 or 8, and children at risk of MEN 2B, as early as 1 year of age.
One can live a normal life without a thyroid gland, taking thyroid hormones for life to replace those that the thyroid would ordinarily produce. And because MEN 2 is a syndrome involving other types of tumors, children who have their thyroid glands removed still need to be monitored for other potential problems.
If a person has a family history of medullary thyroid cancer, consider talking to a genetic counselor. He or she can explain the advantages and disadvantages of genetic testing and the risks and benefits of thyroid surgery.
The exact cause of thyroid cancer is unknown. But is clearly evident that people who have been exposed to a lot of radiation either from the environment or from medical treatment have a greater chance of developing thyroid cancer.
This means that an occasional dental X-ray will not increase the risk of developing thyroid cancer. But past radiation treatment of the head, neck, or chest (especially during childhood) can increase the chances of developing thyroid cancer.
Thyroid Cancer Symptoms or Signs of Thyroid Cancer
Similar to other type of cancers thyroid cancer symptoms or signs of thyroid cancer are not evident in the early stage. As the cancer grows, a small lump or nodule can be felt in the neck. The vast majority of thyroid nodules are caused by benign conditions, but about one per cent of these lumps represent early stages of thyroid cancer. If the cancer spreads, it can cause symptoms that include:
- Swallowing becomes a problem
- Sore throat
- Difficulty speaking in a normal voice
- Hoarseness in the voice that does not get better and is not related to a cold.
- Also a cough that continues and is not related to a cold.
- Swollen or Enlarged lymph nodes in the neck
- Pain in the throat and/or neck sometimes spreading up to the ears
- A lump sometimes growing rapidly at the base of the neck
- A lump elsewhere in your neck
- A lump, or nodule, in the front of the neck near the Adam’s apple;
- Trouble breathing
- Sometimes constant wheezing.
These symptoms are not sure signs of thyroid cancer. Other conditions including a benign thyroid nodule, an infection or inflammation of the thyroid gland and a benign enlargement of the thyroid (goiter) can cause similar problems, all of which are highly treatable. But anyone with these symptoms should see a doctor as soon as possible.
Remember, 99% of nodules in the thyroid gland are benign, but only the doctor can determine if a lump in the person’s neck is cancerous or not. Even the symptoms above can be caused by infections and other benign conditions.
Thyroid Cancer Treatments
The goal of thyroid cancer treatments for thyroid cancer is to get rid of the cancer cells in the body.
The treatment option depends on age, the type of thyroid cancer, the stage of the cancer, and overall general health of the patient.
Most people have surgery to remove part or all of the thyroid gland. Sometimes, a suspicious lump or nodule has to be surgically removed before the existence of cancer is proved.
After surgery, the patient may need treatment with radioactive iodine to destroy any remaining thyroid tissue. Once the patient no longer has all or part of the thyroid gland, then probably they may need to take thyroid hormone medicines for the rest of their life.
These medicines replace necessary hormones that are normally made by the thyroid gland and prevent the patient from having hypothyroidism which means too little thyroid hormone.
There are four major treatments available for patients with thyroid cancer.They are as follows:
- Surgery (taking out the cancer).
- Radiation therapy (using high-dose x-rays or other high-energy rays to kill cancer cells).
- Chemotherapy (using drugs to kill cancer cells).
- Hormone therapy (using hormones to stop cancer cells from growing).
Surgery is the most common treatment of thyroid cancer. It is used to remove the part of the thyroid gland that contains cancer. Removing one part (lobe) is called a lobectomy. Removing both lobes is called a thyroidectomy.
A doctor may remove the cancer using one of the following operations:
- Lobectomy is a type of surgery which removes only the side of the thyroid where the cancer is found. Lymph nodes in the area may be taken out for biopsy.
- Near-total thyroidectomy removes the entire thyroid except for a small part.
- Total thyroidectomy removes the entire thyroid.
- Lymph node dissection removes lymph nodes in the neck that contain cancer.
Thyroid-stimulating hormone (TSH) suppression therapy may be used if the patient is not healthy enough to have surgery. TSH suppression therapy reduces the TSH in the body, which may help prevent the growth of any remaining cancer cells.
Radiation therapy uses high-energy x-rays to kill cancer cells and shrink tumors. Radiation for thyroid cancer may come from a machine outside the body (external radiation therapy) or from drinking a liquid that contains radioactive iodine.
Because the thyroid takes up iodine, the radioactive iodine collects in any thyroid tissue remaining in the body and kills the cancer cells. Radioactive iodine is used after surgery to destroy any remaining thyroid tissue.
After the thyroid surgery is completed the patient has to wait for several weeks before having radioactive iodine treatment to destroy any remaining thyroid tissue. During the waiting period, some symptoms of hypothyroidism such as fatigue, weakness, weight gain, depression, memory problems, or constipation may follow.
The patient may also be put on a low-iodine diet before the treatment. That means the patient cannot eat foods that contain a lot of iodine, such as seafood and baked goods. Depleting the body of iodine may make radioactive iodine treatment more effective because the cells become “hungry” for iodine.
Chemotherapy uses drugs or medications to kill cancer cells. The doctor may recommend chemotherapy following surgery to kill any cancer cells that may have spread outside the thyroid.
Treatment often involves receiving two or more drugs in different combinations Chemotherapy may be taken by pill orally, or it may be put into the body by a needle in the vein or muscle intravenously. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells outside the thyroid.
Hormone therapy uses hormones to stop cancer cells from growing. It works by interfering with the production or action of particular hormones. Hormones are naturally produced substances that act as chemical messengers to assist in the normal control and functions of the bodies cells.
In treating thyroid cancer, hormones can be used to stop the body from making other hormones that might make cancer cells grow. Hormones are usually given as pills.
Thyroid Cancer Prognosis
Almost all types of thyroid cancers are curable therefore thyroid cancer prognosis is quiet good. In fact, the most common types of thyroid cancer like the papillary and follicular are the most curable. In younger patients, both papillary and follicular cancers can be expected to have better than 97% cure rate if treated appropriately.
Both papillary and follicular cancers are typically treated with complete removal of the lobe of the thyroid which harbors the cancer, also removal of most or all of the other side.
The bottom line, most thyroid cancers are papillary thyroid cancer, and this is one of the most curable cancers of all cancers that humans get.
Medullary cancer of the thyroid is significantly less common, but has a worse prognosis. Medullary cancer tends to spread to large numbers of lymph nodes very early and therefore requires a much more aggressive operation than the more localized cancers such as papillary and follicular.
This cancer requires complete thyroid removal with a dissection to remove the lymph nodes of the front and sides of the neck.
The least common type of thyroid cancer is anaplastic which has a very poor prognosis. Anaplastic thyroid cancer tends to be found after it has spread and is not cured in most cases (it is very uncommon to survive anaplastic thyroid cancer). Often an operation cannot remove the entire tumor.
These patients often require a tracheostomy during the treatment, and treatment is much more aggressive than for other types of thyroid cancer–because this cancer is much more aggressive.