Thyroid Cancer

Your thyroid is located in the front of your neck, just under your Adam's apple. (Read about "Thyroid") The thyroid produces several hormones, including one called thyroxine, which help regulate a number of bodily functions. The American Cancer Society (ACS) says that about one third of all adults will find they have a lump in their thyroid. Ninety-five percent of those lumps are not cancerous, but they can cause the thyroid to malfunction and need to be checked by a doctor. The other five percent will be diagnosed as cancer. (Read about "Cancer: What It Is") ACS says over 19,000 people will get that news each year, the majority of them women. There is a 3 to 1 ratio of women to men who get thyroid cancer. The National Cancer Institute (NCI) calls thyroid cancer the most common cancer of the endocrine system (Read about "Endocrine System"), resulting in about 1 percent of all cancers. The good news is the treatment success rate for thyroid cancer is very high.

Types of cancer

There are four main types of thyroid cancer. They include:

• Papillary - Called the most common type of thyroid cancer by ACS, it represents 60 to 80 percent of thyroid cancers. It develops in the cells that produce the thyroid hormones containing iodine. It is a slow growing cancer that over 80 percent of the time involves just one side of the thyroid. ACS says that 90 percent of the people treated for this cancer live 15 years or more after they find out they have the disease.
• Follicular - Also develops in the cells that make iodine containing hormones. It represents 10 to 30 percent of thyroid cancers. It is more aggressive than papillary and can spread. Once again, it has a high treatment success rate; about 90 percent of people with it live 15 years or more.
• Medullary - The only cancer that forms in the cells of the thyroid that help control the amount of calcium (Read about "Calcium") in our bodies. It is more likely to spread to other parts of the body. It is also the only thyroid cancer with a clear genetic connection (Read about "Genetics"), according to NCI. Five to seven percent of thyroid cancers are this type. Some 80 percent of patients with this cancer are still alive ten years after diagnosis.
• Anaplastic - The most aggressive of the thyroid cancers, grows and spreads quickly. It is relatively rare, responsible for just 2 percent of thyroid cancers. Unfortunately, the survival rate is low as well. ACS says only 3 to 17 percent of patients survive five years after diagnosis.

Symptoms and Risks

The most common symptom of thyroid cancer is a lump. Often that is the only symptom. Also remember, 95 percent of lumps in the thyroid are not cancer but should still be checked by a doctor because they can affect the normal function of the thyroid. (Read about thyroid nodules in "Thyroid" ") Other symptoms according to ACS and NCI can include:

• pain in the neck
• a fullness or tightness in the neck
• problems swallowing or breathing (Read about "Respiratory System")
• hoarseness
• a cough that won't go away and isn't because of a cold

Once again, these symptoms can also indicate other medical conditions and should be checked by a doctor.

Radiation has been identified as one of the major risk factors for thyroid cancer. Years ago, many children were exposed to radiation to treat a number of conditions such as acne or for swollen adenoids or tonsils. (Read about "Acne" "Tonsils & Adenoids") Studies show that those people have an increased risk of thyroid cancers. Exposure to radiation from nuclear fallout in the 1950's is also being studied as a risk factor. The thyroid collects iodine and much of the fallout was in the form of radioactive iodine. There is also evidence according to ACS that there are more thyroid cancers showing up in children who lived near the Chernobyl nuclear plant that exploded in 1986.

Diagnosis and Treatment

The process used to find out if cancer has spread within the thyroid or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. The following tests and procedures may be used in the staging process:

• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. (Read about "CT Scan - Computerized Tomography")
• MRI: MRI uses a powerful magnet linked to a computer. It makes detailed pictures of your neck and chest area. MRI may show whether cancer has spread to lymph nodes or other areas. (Read about "MRI - Magnetic Resonance Imaging")
• Ultrasound exam: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. The picture can be printed to be looked at later. (Read about "Ultrasound Imaging")
• Chest x-ray : An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body. (Read about "X-rays")
• Whole body scan: You may have a whole body scan to see if cancer has spread from the thyroid to other parts of the body.

Ultimately, a biopsy (Read about "Biopsy") may be needed to confirm the existence of cancer. Treatment can then be planned. (Read about "Cancer Treatments")

NCI says surgery is the most common treatment for thyroid cancer. The thyroid is either completely or partially removed. Surgery to remove the entire thyroid is called a total thyroidectomy. Some patients with papillary or follicular thyroid cancer may be treated with lobectomy, in which the lobe with the cancerous nodule is removed. Lymph nodes may also be removed. Some patients who have a lobectomy receive radioactive iodine therapy or additional surgery to remove remaining thyroid tissue.

In addition to surgery, in some types of thyroid cancer, radioactive iodine therapy (also called radioiodine therapy) may be used. This uses radioactive iodine to destroy thyroid cancer cells. External radiation therapy and/or chemotherapy may also be used. (Read about "Radiation Therapy")

Hormone therapy may be another option. In the treatment of thyroid cancer, drugs may be given to prevent the body from making thyroid-stimulating hormone (TSH), a hormone that can increase the chance that thyroid cancer will grow or recur.

Targeted therapy may be another option. It uses drugs or other substances to identify and attack specific cancer cells.

If the cancer has spread, additional surgery or other treatments may be needed. After thyroid surgery, replacement thyroid hormone may be needed by the patient for the rest of their lives.

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For a list of individual types of cancer, see Cancer: What It Is