Thyroid cancer is typically detected when an individual or their physician identifies a lump or nodule in the thyroid gland, often during routine physical examination. Additional symptoms or sign attributable to thyroid cancer are uncommon.
Thyroid cancer begins when healthy cells acquire a genetic change (mutation) that causes them to turn into abnormal cells. Most thyroid cancers develop sporadically, which means for no known reason. Development of thyroid cancer however can occur as a result of radiation exposure and occurs in some hereditary syndromes.1,2
A risk factor is anything that increases a person’s chance of developing cancer. Risk factors can influence the development of cancer, but most do not directly cause cancer. Many individuals with risk factors will never develop cancer and others with no known risk factors will.
Patients with a history of radiation therapy to the head and neck have an increased risk of cancer and other abnormalities of the thyroid gland. Cancer of the thyroid gland may appear as early as 5 years after radiation therapy and may appear 20 or more years later.1,2,3 Radiation exposure as a consequence of nuclear fallout has also been associated with a high risk of thyroid cancer, especially in children.4,5
Risk factors for thyroid cancer include the following:1,2
- Radiation exposure.
- Family history of thyroid disease.
- Multiple endocrine neoplasia (MEN) syndrome.
- RET/BRAF gene mutation.6
- A history of thyroid goiter.
- Female gender.
- Asian race.
Next: Diagnosis & Tests for Thyroid Cancer
1 American Cancer Society: Cancer Facts and Figures 2017. Atlanta, Ga: American Cancer Society, 2017.
2 Carling T, Udelsman R: Thyroid tumors. In: DeVita VT Jr, Lawrence TS, Rosenberg SA: Cancer: Principles and Practice of Oncology. 9th ed. Philadelphia, Pa: Lippincott Williams & Wilkins, 2011, pp 1457-72.
3 Iribarren C, Haselkorn T, Tekawa IS, et al.: Cohort study of thyroid cancer in a San Francisco Bay area population. Int J Cancer 93 (5): 745-50, 2001.
4 Cardis E, Kesminiene A, Ivanov V, et al.: Risk of thyroid cancer after exposure to 131I in childhood. J Natl Cancer Inst 97 (10): 724-32, 2005.
5 Tronko MD, Howe GR, Bogdanova TI, et al.: A cohort study of thyroid cancer and other thyroid diseases after the chornobyl accident: thyroid cancer in Ukraine detected during first screening. J Natl Cancer Inst 98 (13): 897-903, 2006.
6 Salvatore G, Giannini R, Faviana P, et al.: Analysis of BRAF point mutation and RET/PTC rearrangement refines the fine-needle aspiration diagnosis of papillary thyroid carcinoma. J Clin Endocrinol Metab 89 (10): 5175-80, 2004.