Estudo da prevalência de doença autoimune da tireóide em portadoras de câncer de mama

Abstract

Breast cancer is a hormone-dependent neoplasia. In addition to the fact that breast cancer and thyroid disease are more prevalent in the fifth and sixth decades of life, several studies also suggest an association between these two disorders. 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. The frequency and pattern of thyroid disorders were evaluated in 112 patients with breast cancer (G1) and 125 control patients (G2) by analyzing serum thyroidstimulating hormone (TSH), anti-thyroid peroxidase (anti-TPO) antibodies and antithyroglobulin (anti-Tg) antibodies. In addition, the expression of estrogen receptors (ER), progesterone receptors (PR) and human epidermal growth factor receptor 2 (HER2) was assessed in the breast biopsies by immunohistochemistry. The frequency of thyroid disorders, such as changes in TSH levels and/or the presence of positive thyroid antibodies, was not different between the two groups examined (30.4% in G1 and 28.0% in G2) (p=0.69). However, a family history of thyroid disease was more frequent in patients with breast cancer (50.5% in G1 and 28.2% in G2) (p=0.001). Regarding the clinical stage of breast cancer, there was no difference between women with autoimmune thyroiditis and those without thyroid dysfunction (p=0.316). Similarly, there were no differences in hormone receptor (estrogen and progesterone) and HER2 expression between patients who tested positive and negative for antithyroid antibodies (p=0.052 and p=0.549). The data obtained in this study did not reveal a higher frequency of autoimmune thyroid disease in patients with breast cancer compared to controls, and the prevalence of thyroid disorders was similarly elevated in both groups. However, a family history of thyroid disease was higher in those with cancer.