RESUMO
OBJECTIVE: The aim of this study was to analyze the prevalence of thyroid disorders in patients with a positive biopsy for breast cancer prior to specific antitumor treatment. METHODS: The frequency and pattern of thyroid disorders were evaluated in 112 patients with breast cancer (G1) and 125 control patients (G2) by analyzing serum thyroid-stimulating hormone (TSH), anti-thyroid peroxidase antibodies, and anti-thyroglobulin antibodies. In addition, the expression of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2 (HER2) was assessed in the breast biopsies by immunohistochemistry. RESULTS: The frequency of thyroid disorders, such as changes in TSH levels and/or the presence of thyroid antibodies, was not different between the 2 groups examined (30.4% in G1 versus 28.0% in G2) (P = .69). However, a family history of thyroid disease was more frequent in patients with breast cancer (50.5% in G1 versus 28.2% in G2) (P = .001). Regarding the clinical stage of breast cancer, there was no difference between women with autoimmune thyroiditis and those without thyroid dysfunction (P = .316). Similarly, there were no differences in hormone receptor (estrogen or progesterone) and HER2 expression between patients who tested positive and those who tested negative for anti-thyroid antibodies (P = .052 and P = .549, respectively). CONCLUSION: The data obtained in this study did not reveal a higher frequency of autoimmune thyroid disease in patients with breast cancer compared to controls. A family history of thyroid disease was more common in those with breast cancer.
