Background
Thyroid Nodules and Thyroid Cancer
About 60% of the adult population has thyroid nodules, the precursor to thyroid cancer.
About 10% of all thyroid nodules are found to be thyroid cancer on biopsy.
Thyroid cancer is more common in women than in men, with about 75% of all thyroid cancers occurring in women.
The average age of thyroid cancer diagnosis is about 50. However, thyroid cancer is also prevalent in adolescents and young adults as it is the most common cancer in adolescents and young adults ages 16-39.
The most common type of thyroid cancer is papillary thyroid cancer. Other types of thyroid cancer include follicular, Hürthle cell, medullary and anaplastic thyroid cancer.
For patients who have localized papillary or follicular thyroid cancer, 5-year survival is near 100%. For patients with regional disease 5-year survival is 97-99%. For patients with distant disease, 5-year survival is 60-75%.
Other Thyroid Diseases
Hypothyroidism, an underactive thyroid, is the second most common endocrine disorder, disproportionately affecting women and older adults.
The most common cause of hypothyroidism is autoimmune thyroiditis (Hashimoto’s thyroiditis); other causes include surgical removal of part or all of the thyroid gland, radiation treatment, medications (such as amiodarone or lithium) and inflammation of the thyroid.
Thyroid hormone use is widespread, with levothyroxine consistently among the top three most commonly prescribed medications in the United States.
Hyperthyroidism, an overactive thyroid, is most commonly due to an autoimmune process called Graves’ disease; other causes are iatrogenic, toxic multinodular goiter, toxic adenoma and inflammation of the thyroid (thyroiditis).
Persistent hyperthyroidism can be associated with adverse effects, especially in older adults, including cardiac arrhythmias and bone loss.
The frequency of subclinical thyroid diseases, i.e., mild degrees of thyroid dysfunction evident only biochemically, increases with age, especially in women.
