Expression of Thyroid Peroxidase Antibody, Thyroglobulin Antibody, and Thyrotropin Receptor Antibody in Breast Cancer and Their Associations with Clinical Characteristics of Breast Cancer

The relationship between chronic lymphocytic thyroiditis (CLT) and breast cancer was still unclear. We investigated the positivity of thyroid peroxidase antibody (TPO-ab), thyroglobulin antibody (TG-ab), and thyrotropin receptor antibody (TSHR-ab) in 362 patients with breast cancer, 360 patients with benign breast diseases, and 386 healthy controls. Further, we analyzed the associations between TPO-ab, TG-ab, TSHR-ab, and clinical characteristics in coastal residents with breast cancer according to molecular subtype. There were no significant differences in the levels of free triiodothyronine (FT3), free tetraiodothyronine (FT4), thyroid-stimulating hormone (TSH), and the positive rates of TG-ab and TSHR-ab among three groups. The positive rate of TPO-ab in patients with breast cancer was higher compared to patients with benign breast diseases and healthy controls (P=0.002). Axillary lymph node metastasis (ALNM) in breast cancer patients with positive TPO-ab was less frequent than breast cancer patients with negative TPO-ab (P=0.022). The percentage of TNM stage I–II patients with positive TPO-ab were higher than that in patients with negative TPO-ab (P= 0.029). TPO-ab was a predictor for low prevalence of ALNM in breast cancer patients with luminal A subtype (P=0.013) and luminal B subtype (P=0.024), but not for breast cancer patients with HER2 over-expression subtype (P=0.381) and basal-like subtype (P=0.282). Thyroid peroxidase antibody was an independent predictor for the low prevalence of axillary lymph node metastasis in breast cancer patients with luminal A subtype and luminal B subtype.