What is thyroid cancer?
Thyroid cancer is a disease in which the thyroid cells become abnormal, grow uncontrollably, and form tumors. Thyroid cancers are grouped into four types, based on how the cell appears under the microscope. If left untreated, the cancer can spread to other parts of the body.
The thyroid is a butterfly-shaped gland, located at the base of the throat. It has two lobes, the left and the right. The thyroid gland makes hormones that regulate heart rate, blood pressure, body temperature, and metabolism.
The hormones produced by the thyroid also affect the nervous system, muscles, and other organs, and play an important role in regulating childhood growth and development. The thyroid uses iodine, a mineral found in some foods, to make several of its hormones. Diseases of the thyroid gland occur frequently, affecting millions of Americans. The most common diseases are an overactive or an underactive thyroid gland. These conditions are called hyperthyroidism (Grave's disease) or hypothyroidism. Sometimes, lumps or masses may develop in the thyroid glands. Ninety-five percent of these lumps or nodules are non-cancerous (benign), but all thyroid lumps should be taken seriously. A woman's risk of developing thyroid cancer is three times greater than a man's. Most people who develop thyroid cancer are 50 years of age or older, but the disease can affect teenagers and young adults.
Thyroid cancers are grouped into four types, depending on how the cells look under the microscope. The types are papillary, follicular, medullary, and anaplastic thyroid cancers. The cancers grow at different rates, so the aggressiveness of each cancer is different. Papillary cancer develops in the cells that produce thyroid hormones containing iodine. It is a slow-growing cancer and can be treated successfully. About 60-80% of all thyroid cancers are papillary cancers. Follicular cancers also develop in the cells that produce iodine-containing hormones. Many of the follicular cancers have a good cure rate, but if the cancer invades blood vessels or grows into nearby structures in the neck, it may be difficult to control. About 30-50% of thyroid cancers are follicular cancers.
Medullary cancers develop in the parafollicular cells (also known as the C cells). These cells produce a hormone called calcitonin, which does not contain iodine. These cancers are more difficult to control because they have a tendency to spread to other parts of the body. About 5-7% of all thyroid cancers are medullary cancers. Approximately 7% of medullary cancers are caused by the alteration (mutation) of a gene called the RET gene; these cancers can be passed on in families. Anaplastic cancer is the fastest growing of all thyroid cancers. The cells rapidly spread to the different parts of the body. About 2% of all thyroid cancers are anaplastic cancers.
More information on thyroid cancer
What is thyroid cancer? - Thyroid cancer is a disease in which the thyroid cells become abnormal, grow uncontrollably, and form tumors.
What types of thyroid cancer are there? - There are four major types of thyroid cancer: papillary thyroid cancer, follicular thyroid cancer, medullary thyroid cancer, and anaplastic thyroid cancer.
What causes thyroid cancer? - Doctors do not know what causes most cases of thyroid cancer. Exposure to radiation during childhood is a known risk factor for thyroid cancer.
What're the symptoms of thyroid cancer? - The most common symptom of thyroid cancer is a lump, or nodule, that can be felt in the neck. Other symptoms are rare.
What're the risk factors for thyroid cancer? - Risk factors for thyroid cancer include radiation, family history, genetic conditions, sex, reproductive history.
How is thyroid cancer diagnosed? - A test known as the calcitonin test may be ordered if medullary thyroid cancer is suspected. Imaging tests identify any abnormal areas in the thyroid.
What's the treatment for thyroid cancer? - Treatment for thyroid cancer depends on the type of cancer and its stage. Surgery is the most common form of treatment for thyroid cancer.
How to prevent thyroid cancer? - Because many people develop thyroid cancer without having any known risk factors for the illness, this form of cancer is hard to prevent.