Estrogen, Uterine Fibroids, and Thyroid Nodules

Also see:
Quotes: Thyroid, Estrogen, Menstrual Symptoms, PMS, and Infertility
Autoimmune Disease and Estrogen Connection
Hormonal profiles in women with breast cancer
PUFA Increases Estrogen
PUFA Inhibit Glucuronidation
PUFA Promote Cancer
Maternal PUFA Intake Increases Breast Cancer Risk in Female Offspring
Vitamin A: Anti-Cancer and Anti-Estrogen
Toxic Plant Estrogens
The Dire Effects of Estrogen Pollution
Progesterone: Essential to Your Well-Being
Alcohol Consumption – Estrogen and Progesterone In Women
Estrogen, Endotoxin, and Alcohol-Induced Liver Injury
Estrogen Levels Increase with Age
Fat Tissue and Aging – Increased Estrogen
Estrogen Related to Loss of Fat Free Mass with Aging
Bisphenol A (BPA), Estrogen, and Diabetes
Shock Increases Estrogen

“In my own experience, no patient has required a hysterectomy for pathological bleeding unless uterine fibroids were present. If organic problems could be ruled out, as they could in the great majority of cases, thyroid deficiency usually could be detected and treatment with thyroid solved the problem. The need for other surgery may be minimized by adequate thyroid therapy in women with low thyroid function. Cysts on the ovary are common in such women and correction of the thyroid deficiency often eliminates the cysts. Fibroid tumors have been rare in hypothyroid women who have been maintained on adequate thyroid therapy. It is possible to produce fibroids in experimental animals by injection of estrogen, and there is evidence of excess of estrogen in hypothyroid women.” -Dr. Broda Barnes

J Clin Endocrinol Metab. 2001 Mar;86(3):1072-7.
Estrogen promotes growth of human thyroid tumor cells by different molecular mechanisms.
Manole D, Schildknecht B, Gosnell B, Adams E, Derwahl M.
Thyroid tumors are about 3 times more frequent in females than in males. Epidemiological studies suggest that the use of estrogens may contribute to the pathogenesis of thyroid tumors. In a very recent study a direct growth stimulatory effect of 17beta-estradiol was demonstrated in FRTL-5 rat thyroid cells. In this work the presence of estrogen receptors alpha and beta in thyroid cells derived from human goiter nodules and in human thyroid carcinoma cell line HTC-TSHr was demonstrated. There was no difference between the expression levels of estrogen receptor alpha in males and females, but there was a significant increase in expression levels in response to 17beta-estradiol. Stimulation of benign and malignant thyroid cells with 17beta-estradiol resulted in an increased proliferation rate and an enhanced expression of cyclin D1 protein, which plays a key role in the regulation of G(1)/S transition in the cell cycle. In malignant tumor cells maximal cyclin D1 expression was observed after 3 h, whereas in benign cells the effect of 17beta-estradiol was delayed. ICI 182780, a pure estrogen antagonist, prevented the effects of 17beta-estradiol. In addition, 17beta-estradiol was found to modulate activation of mitogen-activated protein (MAP) kinase, whose activity is mainly regulated by growth factors in thyroid carcinoma cells. In response to 17beta-estradiol, both MAP kinase isozymes, extracellular signal-regulated protein kinases 1 and 2, were strongly phosphorylated in benign and malignant thyroid cells. Treatment of the cells with 17beta-estradiol and MAP kinase kinase 1 inhibitor, PD 098059, prevented the accumulation of cyclin D1 and estrogen-mediated mitogenesis. Our data indicate that 17beta-estradiol is a potent mitogen for benign and malignant thyroid tumor cells and that it exerts a growth-promoting effect not only by binding to nuclear estrogen receptors, but also by activation of the MAP kinase pathway.

Endocr J. 2010;57(7):615-21. Epub 2010 May 13.
The relationship between thyroid nodules and uterine fibroids.
Kim MH, Park YR, Lim DJ, Yoon KH, Kang MI, Cha BY, Lee KW, Son HY.
Previous studies suggested that estrogen might have an important role in thyroid nodule formation. Besides, it was recently reported that women with uterine fibroids, which estrogen has effects on, had an increased incidence of thyroid nodules. Our study was to identify the relationship between uterine fibroids and thyroid nodules and to find the factors that may have influences on the occurrence of thyroid nodules. We reviewed the records of 1144 participants who attended health check-ups from 2005 to 2008. Evaluated clinical variables included the size and number of thyroid nodules, presence of uterine fibroids, menopausal status, BMI, smoking, alcohol, medication status, serum levels of cholesterol, LH, FSH, and estradiol. A total of 925 participants were included and 163 (17.6%) subjects had thyroid nodules and uterine fibroids simultaneously. A significant association between both diseases existed (P=0.010), and closer relationship was observed in premenopausal women (n=445, P=0.001). In univariate analysis of systemic E2 level and the incidence of thyroid nodule in premenopausal women, systemic E2 levels had inverse correlation with the incidence of thyroid nodules (P=0.024, OR=0.631, CI: 0.424-0.940). In multivariate logistic regression analysis, older age and the presence of uterine fibroids were the independent factors for the presence of thyroid nodules. Our study suggested that uterine fibroids in women were definitely associated with thyroid nodules and estrogen might have a pivotal role in occurrence of both uterine fibroids and thyroid nodules.