Thyroid cancer is a type of cancer that affects the thyroid gland, which is located in the neck. The thyroid gland produces hormones that regulate the body’s metabolism. Thyroid cancer can occur in people of any age, but it is most common in women over the age of 40. There are several types of thyroid cancer, and the treatment for each type varies. The most common type of thyroid cancer is papillary thyroid cancer, which makes up about 80% of all cases. The second most common type is follicular thyroid cancer, which makes up about 15% of all cases. Treatment for thyroid cancer usually involves surgery to remove the affected gland, as well as radiation therapy and/or chemotherapy.