Your thyroid is a butterfly-shaped gland in your neck, just above your collarbone. It makes hormones that help the body work normally. Anyone can get cancer of the thyroid gland. But certain factors may increase the risk. These include
Being between ages 25 and 65
Being a woman
Being Asian
Having a family member who has had thyroid disease
Having radiation treatments to your head or neck
You should see a doctor if you have a lump or swelling in your neck. Your doctor can order tests to see if you have cancer and, if so, which type. Treatment depends on the type and how far the cancer has spread. They include surgery, radioactive iodine, hormone treatment, radiation therapy or chemotherapy. Some patients receive a combination of treatments.
National Cancer Institute