Thyroid disorders in women with breast cancer

Increasing prevalence of non-malignant thyroid disorders in women with breast cancer has been known for several decades; it is said to be associated with a better prognosis of the cancerous disease. The aim of this work was to analyse associations between thyropathies found in women with breast cancer and particular prognostic factors. A group of 110 women with breast cancer were tested for autoimmune thyroiditis (AIT) and functional changes of the thyroid gland. Presence of thyroid-peroxidase autoantibodies (TPOAb), serum levels of thyroid-stimulating hormone (TSH) and free thyroxine (FT3, FT4) were determined after the surgery but before adjuvant cancer treatment (radiotherapy, chemotherapy or hormone therapy) initiation. Conventionally evaluated prognostic factors of breast cancer, including histological grading and molecular predictive factors (i.e. the status of the hormone receptors and the human epidermal growth factor receptor) were assessed - these were divided into four basic categories. The incidence of AIT and subclinical hypothyroidism in the study group was 37.3% and 20%, respectively, i.e. higher than in the general population. The only correlation found was between thyropathies and the specific prognostic factors was that with G1 breast cancer grading.