Cancer Types - Thyroid Tumors
A nodule found in a man's thyroid is more likely to be cancer than when found in a woman.
What is radioactive iodine treatment?
The thyroid needs iodine to properly produce the thyroid hormones. By administering radioactive iodine to a patient, the thyroid tissue will absorb the altered iodine, which then destroys that thyroid tissue.
The thyroid gland is located in the front of the neck at the base of the throat. Thyroid tumors are either benign (noncancerous) or malignant (cancerous) growths. Examples of benign tumors are adenomas, which secrete thyroid hormone. Malignant tumors are more rare and are more common in women than in men. According to the American Cancer Society (ACS), about 44,670 cases of thyroid cancer were expected to be diagnosed in the U.S. in 2010.
Thyroid adenomas are small growths (nodules) that start in the cell layer that lines the inner surface of the thyroid gland. The adenoma itself secretes thyroid hormone. If the adenoma secretes enough thyroid hormone, it may cause hyperthyroidism. Thyroid adenomas may be treated if they cause hyperthyroidism. Treatment may include surgery to remove part of the thyroid (the overactive nodule).
Cancer of the thyroid occurs more often in people who have undergone radiation to the head, neck, or chest. However, it may occur in people without any known risk factors. Most thyroid cancer can be cured with appropriate treatment. Thyroid cancer usually appears as nodules within the thyroid gland. Some signs that a nodule may be cancerous include:
- Presence of a single nodule rather than multiple nodules
- Thyroid scan reveals the nodule is not functioning
- Nodule is solid instead of filled with fluid (cyst)
- Nodule is hard
- Nodule grows fast
The major types of thyroid cancer are:
- Papillary thyroid cancers. This type of thyroid cancer accounts for 80 percent of all thyroid cancers. It begins in the follicular cells of the thyroid and tends to grow slowly. If found early, it can be cured.
- Follicular thyroid cancer. This type of thyroid cancer accounts for about 10 percent of thyroid cancer cases. It also begins in the follicular cells of the thyroid and tends to grow slowly. It can usually be cured, especially if it is found at an early stage.
- Medullary thyroid cancer. This type of thyroid cancer accounts for about 4 percent of all thyroid cancers. Medullary thyroid cancer begins in the parafollicular cells or C cells. This type of thyroid cancer is easier to control if it is found and treated early, before it spreads to other parts of the body. There are two types of medullary thyroid cancer: sporadic medullary thyroid cancer and familiar medullary thyroid cancer (FMTC). Because familiar medullary thyroid cancer tends to run in families, screening tests for genetic abnormalities in the blood cells may be conducted.
- Anaplastic thyroid cancer. This rare type of thyroid cancer accounts for about 2 percent of all thyroid cancers. Anaplastic thyroid cancer tends to grow and spread very quickly. It is very hard to control.
Early thyroid cancer may not cause any symptoms. As the cancer grows, one of the first signs of thyroid cancer is usually a painless lump or swollen lymph nodes in the neck. Other symptoms may include:
- Hoarseness or loss of voice as the cancer presses on the nerves to the voice box
- Difficulty swallowing as the cancer presses on the throat
- Throat or neck pain that does not go away
- Breathing problems
- A cough that does not go away
However, the symptoms of thyroid cancer may resemble other conditions or medical problems. Always consult your physician for a diagnosis.
In addition to a complete medical history and medical examination, diagnostic procedures for thyroid cancer may include:
- Blood tests. These are done to evaluate the level of thyroid-stimulating hormone (TSH), calcium, calcitonin (a hormone produced by normal C cells of the thyroid gland), and other substances in the blood.
- Thyroid scan. This is a type of nuclear scan that examines the thyroid after a person is given (by mouth or intravenously) a small amount of radioactive material that contains iodine. For a short period, the radioactive material emits radiation. A special camera, called a gamma camera, is used to determine the amount of radiation that has been absorbed by thyroid nodules. Cold nodules are nodules that absorb less radioactive material than the surrounding thyroid tissue, whereas hot nodules are nodules that absorb more radioactive material. Cold nodules may be cancer.
- Ultrasound (also called sonography). This diagnostic imaging technique uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds can be used to look for nodules in the thyroid and help determine if they are fluid-filled (cysts) or solid nodules.
- Biopsy. This procedure involves removing tissue samples (with a needle or during surgery) from the body for examination under a microscope to determine if cancer or other abnormal cells are present.
Specific treatment for thyroid tumors will be determined by your physician based on:
- Your age, overall health, and medical history
- Extent of the disease
- Your tolerance for specific medications, procedures, or therapies
- Expectations for the course of the disease
- Your opinion or preference
Treatment may include one or more of the following:
- Surgery. To remove all or part of the thyroid. Types of thyroid surgery include:
- Total thyroidectomy. Removal of the thyroid and sometimes the nearby lymph nodes.
- Lobectomy. Removal of the lobe with the cancerous nodule. The nearby lymph nodes and part of the remaining thyroid tissue may also be removed.
- Radioactive iodine therapy (also called radioiodine therapy). A therapy in which small amounts of radioactive iodine (I-131) are given (usually in a capsule or liquid) to destroy any thyroid cancer cells that have not been removed by surgery or that have spread to other parts of the body. Radioactive iodine therapy is usually not used to treat medullary or anaplastic thyroid cancer.
- External radiation (external beam therapy). A treatment that precisely sends high levels of radiation directly to the cancer cells. The machine is controlled by the radiation therapist. Since radiation is used to kill cancer cells and to shrink tumors, special shields may be used to protect the tissue surrounding the treatment area. Radiation treatments are painless and usually last a few minutes.
- Hormone therapy. Hormones are given to kill cancer cells, slow the growth of cancer cells, or stop cancer cells from growing. Hormone therapy as a cancer treatment involves taking substances to interfere with the activity of hormones or to stop the production of hormones. Hormone therapy may be used to treat papillary and follicular thyroid cancer. This therapy may also be necessary after surgery or radioactive iodine therapy to replace the natural thyroid hormone.
- Chemotherapy. The use of anticancer drugs to treat cancerous cells. It is used to treat anaplastic thyroid cancer or to relieve symptoms of other types of thyroid cancer. In most cases, chemotherapy works by interfering with the cancer cell’s ability to grow or reproduce. Different groups of drugs work in different ways to fight cancer cells. The oncologist will recommend a treatment plan for each individual.
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