The thyroid is a butterfly-shaped gland located at the front and base of the throat. It is largely responsible for regulating the body's metabolism. An overactive thyroid can cause weight loss; an inactive thyroid can cause weight gain. About 37,000 cases of thyroid cancer are reported each year, according to the American Cancer Society. Although doctors are still unable to determine exactly why some people get thyroid cancer, they do know that it can be caused by radiation exposure. Genetics can play a role, too, along with a host of other risk factors. Thyroid cancer is often successfully treated with surgery, radiation and chemotherapy. On average, 97 percent of people with thyroid disease are still alive five years after diagnosis. The success of treatment can hinge on how early the cancer is detected, the type of thyroid cancer and a patient's general health. Symptoms of thyroid cancer include a lump in the neck, trouble breathing, difficulty swallowing and hoarseness.
Radiation
After explosions in 1986 wracked the Chernobyl nuclear power plant in the former Soviet Union, an estimated 5 million people were exposed to radiation, and rates of thyroid cancer soared, a host of scientific studies found. In the U.S., scientists from the National Cancer Institute in 1997 concluded that America's nuclear testing program in the 1950s and 1960s had produced dangerous radioactive iodine-131 fallout that raised risks of thyroid cancer.
Genetic Conditions
Medical scientists have found that thyroid cancer can be caused by the inheritance of an abnormal gene. Additionally, higher rates of thyroid cancer have been found in among people with genetic conditions such as Gardner syndrome, Cowden disease, and familial adenomatous polyposis (FAP). Thyroid cancer is also more likely to occur in people with a history of goiters and benign thyroid nodules.
Gender and Age
Women are about three times as likely to develop thyroid cancer as men. And thyroid cancer is more likely to strike people over 45 years years old. Scientists suspect that too little or too much iodine in the diet could contribute to the development of thyroid cancer.
