Hormonal correlation with abnormal thyroid function and their auxiliary diagnostic value in breast cancer.

OBJECTIVE: To investigate the association between thyroid hormone levels and pathological characteristics in patients with breast cancer. METHODS: A retrospective analysis was conducted on 120 breast cancer patients who received treatment at the First Affiliated Hospital of Xi'an Jiaotong University between January 2020 and December 2023. A total of 100 healthy individuals undergoing routine physical examinations were enrolled as the control group. Serum levels of free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), thyroglobulin antibody (TG-Ab), and Thyroid peroxidase antibody (TPO-Ab) were measured and compared between the two groups. The diagnostic performance of thyroid hormones for breast cancer was evaluated using receiver operating characteristic (ROC) curve analysis, and correlations between thyroid hormone levels and pathological features of breast cancer were further analyzed. RESULTS: No significant differences were observed in serum FT3, TSH, T3, or T4 levels between the two groups (P = 0.446, 0.594, 0.405 and 0.781, respectively). Compared with healthy controls, patients with breast cancer were observed to have significantly higher FT4 levels and substantially higher TPO-Ab levels, despite both parameters remaining within their normal reference ranges (all P < 0.001). ROC analysis demonstrated that the areas under the curve (AUCs) of FT4 and TPO-Ab for predicting breast cancer were 0.701 and 0.805, respectively. Furthermore, FT4 levels were significantly associated with tumor size, clinical stage, and lymph node metastasis (all P < 0.001). TPO-Ab levels were significantly correlated with tumor size, clinical stage, lymph node metastasis, and the expression of estrogen receptor (ER) and progesterone receptor (PR) (P = 0.006, 0.015, 0.046, 0.048 and 0.017, respectively). Follow-up analysis further revealed that clinical stage, lymph node metastasis, postoperative radiotherapy and chemotherapy, ER and PR expression, as well as FT4 and TPO-Ab levels, were independent factors influencing breast cancer recurrence. CONCLUSION: Serum FT4 and TPO-Ab levels are closely associated with the occurrence, progression, and specific pathological features of breast cancer, demonstrating favorable diagnostic and predictive value. Moreover, they may serve as important potential biomarkers for evaluating the risk of recurrence in patients with breast cancer.