Endocrine Abstracts

Aim and objective: The aims of this study were to determine the incidence of breast cancer molecular subgroups, to investigate the relationship between autoimmune thyroid disease and prognostic and predictive factors in patients who were diagnosed with breast cancer.

Materials and methods: One hundred one patients who were followed up with the diagnosis of breast cancer at our Endocrinology and Medical Oncology Departments were included. Patients are divided into subgroups based on the molecular classification. Patients with high serum levels of thyroid peroxidase antibody (anti-TPO) were considered as autoimmune thyroid disease. Prognostic and predictive parameters such as tumor size, axillary involvement, histological grade, lymphovascular invasion, hormone receptor status, HER2 overexpression were collected. The relationships between autoimmune thyroid disease and tumor’s prognostic and predictive factors were studied.

Results: The prevalence of thyroid autoimmunity was 23.8% (n=24) among with our study group. Patients with autoimmune thyroid disease had a significant lower rate of axillary involvement (37.5% vs 61% [P=0.043], respectively). Other parameters did not differ between patients with and without autoimmune thyroid disease.

Conclusions: We found a favorable association between autoimmune thyroid disease and axillary involvement which is crucial and strongly prognostic parameter of breast cancer prognoses. This supports the idea of thyroid autoimmunity being a favorable prognostic parameter in breast cancer. Further studies are necessary to investigate the reasons of protective or predictive effect of high anti thyroid peroxidase levels in breast cancer patients.