What causes medullary thyroid carcinoma?
MTC is most often caused by changes in your genes. Genes are little pieces of information that tell your body what to do or make. You may have been born with the genes that cause MTC. Having a close family member who has had MTC increases your risk for having this condition. Your cause of MTC may be unknown. The following may increase your risk of having MTC: • Thyroid disease: Having too much thyroid hormone or an autoimmune thyroid problem (your body attacks your thyroid). • Previous radiation therapy: Head or neck radiation therapy, earlier in life, increases your risk of having MTC.
