Introduction: Breast cancer is the most common malignancy in women and is one of the leading causes of death in women. Hence, the study of factors involved in the incidence and progression of disease is of great importance. In this study, the relationship between breast cancer and thyroid disorders will be discussed.
Methods: In a case-control study, 86 women with confirmed breast cancer and 50 age-matched healthy women as controls were studied for 12 months in the Cancer Research Center, Imam Reza hospital, Mashhad University of Medical Sciences, Iran. After examination of the thyroid, serum level of Thyrotropin (TSH), Thyroxine (T4), Triiodothyronine (T3) and Anti-Thyroid Peroxidase Antibody (anti-Tpo AB) were tested by radioimmunoassay. The results were compared between the two groups and different pathological subtypes of breast cancer.
Results: Mean serum TSH level was not significantly different between the two groups, but the mean serum levels of T4 and anti-Tpo AB was higher in patients (p<0.05). Increased levels of TSH and T4 were observed in 5.8% and 2.3% of the patient and 12% and 8% of the control group, respectively. Also, decreased TSH and T4 levels were observed in 7% and 2.3% of the patient and 5% and 0% of the control group, respectively. As well, increased levels of T3 and anti-Tpo AB were observed in 0% and 20.9% of patients and in 4% and 8% of the control group, respectively.
Conclusion: Although there was a significant difference between the groups regarding the anti-Tpo AB level, but no obvious connection between thyroid function and breast cancer was found in this study. Therefore, studies with larger sample sizes are required to achieve more qualified results.