It is a slow-growing cancer and can be treated successfully. 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. 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.
Anaplastic cancer is the fastest growing of all thyroid cancers.
The cells rapidly spread to the different parts of the body. The rate of thyroid cancer is also higher in whites than in African Americans. Exposure to radiation during childhood is a known risk factor for thyroid cancer. In the 1950s and 1960s, radiation was used to treat acne and to reduce swelling and infection of organs in the neck, such as the tonsils, adenoids, and lymph nodes. Recent studies have proved that people who received radiation to the head and neck during their childhood have a higher than average chance of developing thyroid cancer.