甲状腺激素影响着组织的发育和生长,可能还会改变雌激素,催乳激素及化学致癌物的代谢作用,从而防御瘤细胞的生长发育。还有一种假设认为甲状腺激素可拮抗雌激素对乳腺组织的激增效应。据说甲状腺机能亢进即是一种防御措施,它通过增加性类固醇激素结合蛋白、降低雌激素对乳房组织的活性以及增加雌酮-雌二醇的代谢作用以减弱雌激素等作用来抵抗乳腺癌的发生。相反,甲状腺机能低下时,乳房上皮组织可能对雌激素、催乳激素和致癌物趋于敏感,进而卵巢也对促性腺激素的刺激更敏感,从而导致雌激素分泌增加。因而,甲状腺机能低下被认为是对乳腺癌的生长,转移 Thyroid hormones affect the development and growth of tissues, may also change the estrogen, prolactin and chemical carcinogens metabolism, thereby preventing the growth of tumor cells. There is also a hypothesis that thyroid hormone can antagonize the estrogen on breast tissue surge effect. Hyperthyroidism is said to be a defense against breast cancer by increasing the amount of sex steroid-binding protein, reducing the activity of estrogen on breast tissue, and increasing the estrogen-estradiol metabolism to attenuate estrogen occur. Conversely, when hypothyroidism occurs, the mammary epithelium may be susceptible to estrogen, prolactin, and carcinogens, and the ovaries are also more sensitive to gonadotrophin stimulation resulting in increased estrogen secretion. Thus, hypothyroidism is considered to be the growth and metastasis of breast cancer