Thyroid Cancer develops when cells in the Thyroid Gland undergo genetic changes (mutations). The causes of such mutations are not clear. The mutation can cause the thyroid cells to grow and multiply at a rapid rate. In addition, the cells may lose their ability to die and recycle as normal cells would. This uncontrollable growth of malignant tissue forms a mass (tumor). In addition, the mutated cells can invade nearby tissue and can spread into other parts of the body.
According to the National Cancer Institute, approximately 37,000 people are diagnosed with Thyroid Cancer each year. Although the rate of Thyroid Cancer appears to be increasing, it is thought that this results from new technology that allows for diagnosing small thyroid cancers that may not have been discovered previously.
Although the causes of Thyroid Cancer are not clear, certain risk factors have been associated with increased chance of developing Thyroid Cancer. These risk factors include:
- Radiation exposure Sources of such radiation include medical treatments and radiation fallout from power plant accidents or nuclear weapons.
- Family history Several inherited conditions have been linked to various types of Thyroid Cancer.
- Gender Women are approximately three times as likely as men to develop Thyroid Cancer.
In general, Thyroid Cancer does not present any signs or symptoms early in the disease. As the cancer grows, it may begin to cause symptoms. Symptoms may vary depending on the type of Thyroid Cancer. They include:
- A mass in the thyroid that can be felt through the skin (nodule)
- Difficulty swallowing
- Enlargement of the Thyroid Gland
- Hoarse voice or a change in the voice
- Neck or throat pain
- Swollen lymph nodes in the neck
Types of Thyroid Cancer:
The type of Thyroid Cancer determines the treatment and prognosis. Types of Thyroid Cancer include:
Papillary Thyroid Cancer
Papillary Thyroid Cancer is the most common, accounting for about 80 percent of all Thyroid Cancers. Papillary Thyroid Cancer can develop at any age, but is most commonly diagnosed in women ages 30 to 50. It spreads slowly and is the least dangerous type of Thyroid Cancer. In general, when diagnosed early, Papillary Thyroid Cancer has a high cure rate.
Follicular Thyroid Cancer
Follicular Thyroid Cancer accounts for about 20 percent of all Thyroid Cancers. Hurthle cell cancers are considered to be a variant of this type of Thyroid Cancer. Follicular Thyroid Cancer typically occurs in people older than 50.
Medullary Thyroid Cancer
Medullary Thyroid Cancer accounts for about 5-10 percent of Thyroid Cancers. It is a cancer of non-thyroid cells that are normally present in the Thyroid Gland. Medullary Thyroid Cancer may be associated with inherited genetic syndromes that include tumors in other glands. Once diagnosed, genetic testing is recommended in order to identify whether the patient has the familial form. If they do, their family members must also be tested to see if they carry the gene. Most Medullary Thyroid Cancers are not associated with inherited genetic syndromes.
Anaplastic Thyroid Cancer
Anaplastic Thyroid Cancer is the most dangerous form of Thyroid Cancer. It is rare and spreads quickly to invade nearby structures such as the windpipe (trachea). It is associated with a poor prognosis. Anaplastic Thyroid Cancer typically occurs in people that are 60 years of age or older.
Thyroid Lymphoma develops in the immune system cells in the Thyroid Gland. Thyroid Lymphomas constitute approximately 5% of all thyroid neoplasms. Thyroid Lymphoma is a highly curable malignancy if diagnosed promptly and managed correctly. They are more common in women and usually affect patients with a median age of 60 years.
Surgical removal of part or all of the Thyroid Gland is usually the treatment of choice for Thyroid Cancer. Depending on the type of cancer, the surgery may also include removal of surrounding lymph nodes and may be followed by radioactive iodine treatment.