The statements made in our article are based on findings published in the medical journal articles listed. They argue for a rethinking about estrogen and breast cancer. As we state, the issue is complex. However, an extensive medical literature discusses the negative effects of estrogen deficiency, especially in women who have had a hysterectomy before age 60. These effects include increased risk for: osteoporosis, atherosclerosis, dementia, sexual dysfunction and mortality. Estrogen use, prior to age 60, by women after hysterectomy reduces these risks. With respect to reducing breast cancer risk, estrogen therapy is effective in women of all ages tested.
Unfortunately, fear of breast cancer and misunderstanding of the difference between taking estrogen-only therapy vs estrogen combined with an estrogen-modifying hormone (progestogen) has led to estrogen-avoidance. This has been costly for these women, impairing quality of life and increasing risk of disease and mortality. That estrogen therapy does not increase the risk for developing breast cancer is the conclusion drawn from multiple studies including the Women’s Health Initiative and is the conclusion drawn by major menopause and endocrine societies.
References Related to Estrogen and Breast Cancer
1. Jordan CV, Ford LG. Paradoxical clinical effect of estrogen on breast cancer risk: a “new” biology of estrogen-induced apoptosis. Cancer Prev Res 2011;4(5):633-637.
2. Carroll JS, Meyer Ca, Song J, et al. Genome-wide analysis of estrogen receptor binding sites. Nature Genetics 2006; 38:1289-1297
3. Ellis MJ, Gao F, Dehdashti F, et al. Oral estradiol therapy of hormone receptor-positive, aromatase inhibitor-resistant advanced breast cancer. JAMA 2009. 302:774-780.
4. Anderson GL, Chlebowski RT, et al Conjugated equine oestrogen and breast cancer incidence and mortality in postmenopausal women with hysterectomy:extended follow-up of the Women’s Health Initiative randomised placebo-controlled trial. Lancet Oncol 2012; 13:476-486. Also: Chlebowski RT, Anderson GL. Changing Concepts: Menopausal Hormone Therapy and Breast Cancer. JNatlCancerInst 2012;104:517-527.
5. O’Brien KM, Fei C, Sandler DP, et al. Hormone Therapy and Young-Onset Breast Cancer. Am J Epidemiology 2015;181:799-807.
6. Schierbeck LL, Rejnmark L, Tofteng CL, et al. Effect of hormone replacement therapy on cardiovascular events in recently postmenopausal women: randomised trial. BMJ 2012;345:e6409
7. Domchek SM, Friebel TM, Singer CF, et al. Association of risk reducing surgery in BRCA 1 or BRCA 2 mutation carriers with cancer risk and mortality. JAMA 2010;304(9):967-975; also, Domchek SM et al, American Society for Clinical Oncology. Chicago, 2012.
8. Rebbeck TR, Friebel T, Wagner T, et al. PROSE study Group. Effect of short-term hormone replacement therapy on breast cancer risk reduction after bilateral prophylactic oophorectomy in BRCA1 and BRCA2 mutation carriers. J Clin Oncol.2005;23(31):7804-7810
9. Baber RJ et al. 2016 Recommendations on women’s midlife health and menopause hormone therapy. Climacteric 2016;19 (2):109-151.