Correlation between triodothyronine levels and cancer cell proliferation in high Ki-67 estrogen receptor-positive breast cancer patients.

e11073 Background: Although thyroid hormone is a critical regulator of cell growth, differentiation and survival during development, the relationship between thyroid hormone status and breast cancer has not been adequately explored. Recent findings suggest that T3 administration reduces cancer cell proliferation depending on the type of tumor cell line with aggressive tumors to be more sensitive to thyroid hormone treatment. Thus, the present study investigated the potential relationship between thyroid hormone levels and strong prognostic factors (such as tumor size, nodal status, and Ki67) in estrogen receptor positive (ER+) breast cancer patients. Methods: 86 ER(+) breast cancer patients were studied. Levels of TSH (μΙU/ml), FT3 (pg/ml) and FT4 (ng/ml) were measured in all patients before surgery. After surgical excision of the tumor, samples were taken for histopathological analysis to determine tumor size, an index of cell proliferation Ki67 and HER2 receptor expression. HER2 receptor when amplified,...