Thyroid cancer (patient information)

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Overview
Thyroid is a butterfly-shaped gland in the neck which makes hormones to help the body work normally. Thyroid cancer is a cancer that starts in the thyroid gland. Thyroid cancer doesn't have any early symptoms. With the development of tne cancer, usual symptoms include a lump that can be felt through the skin on your neck, hoarseness, difficulty swallowing, pain in the neck and throat and swollen lymph nodes in the neck. Treatments include surgery, radiation therapy, chemotherapy, thyroid hormone therapy or a combination of them.

What are the symptoms of Thyroid cancer?
Early thyroid cancer does not have any symptoms. As the tumor grows larger, people may notice one or more of the following symptoms:


 * A nodule, lump, or swelling in the neck
 * Pain in the front of the neck
 * Hoarseness or other voice changes
 * Trouble swallowing
 * Breathing problems
 * Continuous cough

Other health problems may also cause these symptoms. Only a doctor can tell for sure. A person with any of these symptoms should tell the doctor so that the problems can be diagnosed and treated as early as possible.

Diseases with similar symptoms are listed in the following:


 * Nodular goiter
 * Thyroid adenoma
 * Thyroid cysts
 * Chronic thyroiditis

What causes Thyroid cancer?
People who have had radiation therapy to the neck are at higher risk. Radiation therapy was commonly used in the 1950s to treat enlarged thymus glands, adenoids and tonsils, and skin disorders. People who received radiation therapy as children are at increased risk for developing thyroid cancer.

Thyroid cancer can occur in all age groups.

Other risk factors are a family history of thyroid cancer and chronic goiter.

There are several types of thyroid cancer:


 * Anaplastic carcinoma (also called giant and spindle cell cancer) is the most dangerous form of thyroid cancer. It is rare, and does not respond to radioiodine therapy. Anaplastic carcinoma spreads quickly.
 * Follicular carcinoma accounts for about 10% of all cases and is more likely to come back and spread.
 * Medullary carcinoma is a cancer of nonthyroid cells that are normally present in the thyroid gland. This form of the thyroid cancer tends to occur in families. It has been linked with several specific genetic mutations. It requires different treatment than other types of thyroid cancer.
 * Papillary carcinoma is the most common type, and usually affects women of childbearing age. It spreads slowly and is the least dangerous type of thyroid cancer.

Who is at highest risk?
Clinical data have suggested that the development of thyroid cancer is related to several factors.


 * A diet low in iodine: Clinical survey show follicular thyroid cancers are more common in areas where people's diets are low in iodine.
 * Radiation: Scientists has proven that radiation exposure is a risk factor for thyroid cancer. Such radiation includes medical treatments and radiation fallout from power plant accidents or nuclear weapons.
 * Hereditary conditions: Studies show people with certain inherited medical conditions such as familial medullary thyroid carcinoma (FMTC), Gardner syndrome, Cowden disease, and familial adenomatous polyposis (FAP) are at higher risk of developing thyroid cancer.
 * Gender: Contrary to other cancers, thyroid cancers occur more often in women than in men.
 * Age: Clinical data show that papillary and follicular thyroid cancer are usually found in people between the ages of 20 and 60 years.

Diagnosis
Your doctor will perform a physical exam. This may reveal a lump in the thyroid, or swollen lymph nodes in the neck.

The following tests may be done:


 * Calcitonin blood test to check for medullary cancer
 * Thyroglobulin blood test to check for papillary or follicular cancer
 * Laryngoscopy
 * Thyroid biopsy
 * Thyroid scan
 * Ultrasound of the thyroid

This disease may also affect the results of the following thyroid function tests:


 * T3
 * T4
 * TSH

When to seek urgent medical care?
Call your health care provider if symptoms of thyroid cancer develop.

Treatment options
In order to diagnose thyroid cancer, your doctor may suggest you the following tests:
 * Thyroid hormones tests: Thyroid hormones including F3, F4, FF3, FF4 and TSH (thyroid-stimulating hormone) are needed to assess thyroid gland function.
 * Tumor markers: Test for carcinoembryonic antigen (CEA) can sometimes help tell if medullary thyroid carcinoma (MTC) is present.
 * Fine needle aspiration biopsy: The doctor places a thin, hollow needle directly into the nodule to take out cells and repeats twice or three times to receive samples from several areas of the nodule. Then these cells can be checked under a microscope to see whether cancerous or benign.
 * Thyroid gland radioiodine scan: During this test, the doctors put substances with small amounts of radiation into your body and detect the location of the substances. The test can help locate abnormal cells in the body.
 * Computed tomography (CT) scan and biopsy: CT scans are often used to diagnose thyroid cancer. It can help determine the location and size of thyroid cancers and whether they have spread to nearby or distant areas. These are helpful for identifying the stage of the cancer and in determining whether surgery is a good treatment option. CT scans can also be used to guide biopsy and a biopsy sample is usually removed and looked at under a microscope.
 * Magnetic resonance imaging (MRI): An MRI uses magnetic fields but it is a different type of image than what is produced by computed tomography (CT) and produces very detailed images of soft tissues such as the thyroid glands. Like computed tomography (CT), a contrast agent may be injected into a patient’s vein to create a better picture.
 * Positron emission tomography (PET) scan: When doing this test, a small amount of a radioactive medium is injected into your body and absorbed by the organs or tissues. This radioactive substance gives off energy which in turn is used to produce the images. PET can provide more helpful information than either CT or MRI scans. It is useful to see if the cancer has spread to the lymph nodes and it is also useful for your doctor to locate where the cancer has spread.

Patients with thyroid cancer have many treatment options. The selection depends on the stage of the tumor. The options are surgery, radiation therapy, chemotherapy, thyroid hormone treatment, or a combination of these methods. Before treatment starts, ask your health care team about possible side effects and how treatment may change your normal activities. Because cancer treatments often damage healthy cells and tissues, side effects are common. Side effects may not be the same for each person, and they may change from one treatment session to the next.


 * Surgery: Surgery is the main treatment for thyroid cancer. Usually, surgery of removing the tumor and all or part of the remaining thyroid gland is recommended.
 * Radiation therapy: It includes radioactive Iodine (Radioiodine) therapy and external beam radiation therapy. Radioactive iodine (RAI) known as I-131 can be taken into the body to destroy the thyroid gland and any other thyroid cells including cancer cells. During external beam radiation therapy, the doctors use high-energy rays to destroy cancer cells or slow their rate of growth.
 * Chemotherapy: Because chemotherapy is seldom helpful for most types of thyroid cancer, it is always combined with external beam radiation therapy for anaplastic thyroid cancer.
 * Thyroid hormone therapy: This treatment is to take daily pills of thyroid hormone. The aim is to help maintain the body's normal metabolism (by replacing missing thyroid hormone) and prevent some thyroid cancers from returning.

Where to find medical care for thyroid cancer?
Directions to Hospitals Treating thyroid cancer

Prevention of Thyroid cancer
The reasons for the development of thyroid cancer are not clear. Epidemiological data show the following may be helpful:


 * Avoidance of diets low in iodine
 * Avoidance of radiation exposure
 * Genetic blood tests for people with a family history of familial medullary thyroid carcinoma (MTC)

What to expect (Outlook/Prognosis)?
The prognosis of thyroid cancer depends on the following:


 * The stage of the cancer: the size of the tumor, whether the cancer has spread outside the thyroid gland
 * Whether or not the tumor can be removed by surgery
 * The patient’s general health

Possible complications

 * Injury to the voice box and hoarseness after thryoid surgery
 * Low calcium levels from accidental removal of the parathyroid glands during surgery
 * Spread of the cancer to the lungs, bones, or other parts of the body