Thyroid Cancer

The thyroid is a large bow-tie shaped endocrine gland that is found in the human body just below the Adam's apple. The thyroid acts as a cybernetic agent in the human body by steering the rate at which calories are burned. It controls the making of proteins by the body and the sensitivity of the body to hormones. It does not operate independently but is controlled by the pituitary gland and the hypothalamus gland.

To carry out its functions the thyroid manufactures a number of thyroid hormones including thyroxine, triiodothyronine (T3), calcitonin. The hormone thyroxine (T4) regulates the metabolic rate in the body. It also affects the growth and the function of other systems in the body. Triiodothyronine works with thyroxine to affect metabolic rates as well as growth rates in the body.

The thyroid uses iodine to manufacture both thyroxine and triiodothyronine. Without sufficient quantities of iodine the body will develop goiter and have other serious health consequences. Sea salt is a vital source of iodine. It is also found in fish. People living in area remote from the sea have often had goiter. However iodine is easily added to table salt. The Kiwanis Club International has underway a service project to eliminate goiter by building iodinated salt factories around the world whereever they are needed.

Thyroid disorders include hyperthyroidism, hypothyroidism, Graves disease (called Basedow's disease or Graves-Basedow disease in parts of Europe), and other disorders. Hyperthyroidism is a condition popularly called an overactive thyroid. It is caused by the over production of thyroid hormones. The overproduction causes excessive metabolism which increases the temperature and the speed of the biochemistry of the body.

The underproduction of thyroid hormones by the thyroid gland is called hypothyroidism. It is relatively common in people over sixty years of age in the Northern Hemisphere. Its symptoms are varied but usually are presented as a variety of impaired psychological or physiological functions.

Cancer is another of the diseases of the thyroid gland. There are four major types of thyroid cancer. The follicular, medullary and anaplastic forms of thyroid cancers are histological types. The most common type is papillary carcinoma. It seems to be associated strongly with radiation. It usually arises as an irregular solid or cystic mass inside of normal thyroid tissue. It is usually curable with a ten year survival rate in over eighty percent of cases. If it metastasizes it spreads to the lymph nodes in the neck as cervical metastasis. This expansion of the area of the disease is treatable but often reoccurs and has to be treated again. The reoccurrence of the cervical metastasis does not increase the mortality rate.

Papillary carcinoma does not usually spread; however, in cases where it does spread the prognosis is guarded. The most common site for the spread of papillary carcinoma beyond the thyroid and the cervical lymph nodes is to the lung or to bone.

Follicular carcinoma is much more malignant than papillary carcinoma. It often metastasizes with serious consequences if the invasion is vascular with resulting spread to the lungs, bone, brain, liver bladder and skin. It usually occurs in people between 40 and 60 years of age. The prognosis is directly related to the tumor size. The disease has been associated with radiation exposure only rarely. Women are much more likely to get it than are men. It can be cured with radiation therapy. The younger the patient the better is the general results for the patient with a cure rate of 95 percent.

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