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April 4, 1977

Breast Cancer and Thyroid Therapy: Statement by the American Thyroid Association

Author Affiliations

From the Education Committee, American Thyroid Association, Mayo Clinic, Rochester, Minn.

JAMA. 1977;237(14):1459-1460. doi:10.1001/jama.1977.03270410059023

IT HAS recently been reported1 that, among patients undergoing mammography at a hospital in Detroit, the prevalence of breast cancer was higher in women receiving thyroid hormone therapy than in those who were not. Prevalence of breast cancer was said to increase with increasing duration of thyroid hormone treatment, particularly in nulliparous women. Since the time that this report appeared and was widely publicized by the news media, many patients have expressed concern that the thyroid hormone they are taking may be dangerous, and they have inquired as to whether such treatment should be stopped.

The American Thyroid Association, whose membership comprises physicians and basic scientists interested in the thyroid and its diseases, views the aforementioned article with concern, both because of its implication of a possible basic relationship between thyroid therapy and breast cancer and because of its potential impact on the treatment of patients who require thyroid