Correlative Study on the Association Between Breast Cancer and Autoimmune Thyroid Disease

This study aims to investigate the correlation between breast cancer and autoimmune thyroid diseases.

A cross-sectional observational study enrolled 100 breast cancer patients at Zhongshan Hospital of Xiamen University from March 2020 to October 2021. Patients were categorized into benign and malignant groups based on tumor pathology. Additionally, 100 healthy female participants underwent physical examinations at the hospital's outpatient center during the same period as controls. The incidence of autoimmune thyroid diseases was assessed via B-type ultrasound, thyroxine level examination, and biopsy. Statistical analyses explored the relationship between autoimmune thyroid diseases and breast cancer.

The pathological type of the malignant group was more severe than that of the healthy group. Although the levels of triiodothyronine (T3), thyroxine (T4), and free thyroxine (FT4) in the malignant group fell within the normal range, the concentrations of T3 and T4 in the malignant group were significantly lower than those in the benign and healthy groups. Additionally, the levels of FT4 and antibodies (anti-thyroid peroxidase [anti-TPO] and anti-thyroglobulin [anti-TG]) were significantly higher in the malignant group compared to the benign and healthy groups, demonstrating statistical significance (P < .05). Conversely, the concentrations of free triiodothyronine (FT3) and thyroid-stimulating hormone (TSH) in the malignant group showed no statistical significance (P > .05). Furthermore, the levels of T3 and T4 did not correlate with the expression of estrogen receptor (ER) and progesterone receptor (PR) in the study group (P > .05). However, both hormone levels were lower in patients with negative HER-2 expression and those with lymph node metastasis (P > .05).

Autoimmune thyroid disease correlates with breast cancer occurrence. Thyroid hormone and autoantibody levels aid clinical monitoring and prognosis. Positive anti-TG and anti-TPO expressions, along with T3, T4, and FT4 alterations, impact patients.