Is There a Connection Between Thyroid Disease and Breast Cancer?
Posted: Wednesday, May 6, 2020
Chiara Dobrinja, MD, PhD, of the University of Trieste, Italy, and colleagues found that women with primary breast cancer appear to have an increased risk of autoimmune disorders, especially when diagnosis occurs in the premenopausal stage. The report, published in BMC Endocrine Disorders, concluded that prospective studies are necessary to determine causality between breast cancer and thyroid disease.
The authors retrospectively studied a total of 786 women and 7 men treated for primary breast cancer. Patient medical histories were evaluated for coexisting thyroid diseases, including hyperthyroidism, hypothyroidism, benign thyroid disease, thyroid cancer, and thyroid immunity, as well as menopausal status at the time of diagnosis.
Coexisting thyroid diseases were reported in 161 cases (20.3%); 151 cases were benign, and 10 patients presented with thyroid carcinoma. The investigators noted thyroid autoimmunity in 51 patients. Hypothyroidism was found in 88 patients; hyperthyroidism, in 19 patients; and 54 patients showed normal thyroid functioning.
Although there was no correlation between age and thyroid disease (P = .16), women who were diagnosed with breast cancer before menopause were significantly more likely to have thyroid autoimmune diseases than women who were diagnosed after menopause (45% vs. 29%, P = .05). The study authors did not find any statistical relationships between breast cancer molecular profiles and thyroid autoimmunity (P = .26) or altered thyroid function (P = .63). However, breast cancer stage was related to both thyroid autoimmunity (P = .04) and thyroid function (P < .001), where more than half of women affected by benign thyroid disease had stage I breast cancer and more aggressive breast cancers were found in patients with hypothyroidism.
Disclosure: The study authors reported no conflicts of interest.