TSH receptor antibodies have predictive value for breast cancer - retrospective analysis

Abstract

Background: Associations between breast cancer and thyroid disorders are reported in numerous studies. Relationships between thyroperoxidase antibodies (TPOAb), thyroglobulin antibodies (TgAb) and breast cancer have been previously demonstrated. However, no analysis has been performed concerning an association between thyrotropin (TSH) receptor antibodies (TSHRAb) and breast cancer. The aim of the study was to evaluate the prevalence of breast cancer or benign breast tumors in patients with Graves' disease and to analyze a possible relationship between Graves' disease and these two groups of breast diseases with emphasis to epidemiology and laboratory findings.

Patients and methods: Clinical and laboratory details of 2003 women hospitalized for endocrine disorders were retrospectively analyzed, using an unpaired Student's t-test, logistic regression analysis, χ2 test of independence or the two-sided ratio comparison test.

Results: The coexistence of Graves' disease and breast cancer was statistically significant. We observed TSHRAb and TgAb more frequently in patients with breast cancer. We found that TSHRAb is the only variable possessing predictive value for breast cancer.

Conclusions: The strong relationship between Graves' disease and breast cancer is proposed. We suggest that TSHRAb could be described as a positive determinant of breast cancer. The present data call attention to the usefulness of screening for breast cancer in long-term follow-up of patients with autoimmune thyroid disorders, especially of those with Graves' disease. Similarly, screening for autoimmune thyroid disorders should be performed in patients with nodular breast disease. Additionally, the article draws ideas for further research in order to develop targeted treatment for more successful outcome in patients with breast cancer.

Figure 1

Levels of hormones in patients with breast cancer, with benign breast tumors and in controls. Levels of hormones in: patients with breast cancer (BC), patients with benign breast tumors (BBT) or controls (C), expressed as mean ± SD; Statistical analysis with Student’s unpaired t-test; ns, non-significant.

Figure 2

Levels of TSHRAb in patients with breast cancer, with benign breast tumors and in controls. Levels of TSHRAb in: patients with breast cancer (BC), patients with benign breast tumors (BBT) or controls (C), expressed as mean ± SD; Statistical analysis with Student’s unpaired t-test; ns, non-significant.

Figure 3

TgAb and TPOAb levels in patients with breast cancer, benign breast tumors and in controls. Levels of TgAb and TPOAb in: patients with breast cancer (BC), patients with benign breast tumors (BBT) or controls (C), expressed as mean ± SD; Statistical analysis with Student’s unpaired t-test; ns, non-significant.

Figure 4

Trends in occurrence of breast cancer, benign breast tumors and Graves’ disease. Distribution of breast cancer (BC) or benign breast tumors (BBT) in relation to age intervals and in comparison to Graves’ disease, expressed as linear trends.