Scientific research has established that a causal relationship exists between estradiol and cancer, with estradiol, a hormone, increasing the risk of cancer by promoting the malignant growth of breast cells. This negative causal relationship is most likely when there is an abundance of insulin in the body. Estradiol, a form of estrogen, specifically triggers the expansion of certain MCF-7 breast cells that have estrogen receptors (ER), scientists have found. Researchers believe these ER-positive cells, when stimulated, spark an unwarranted cell growth cycle — unless there’s an absence of insulin. Without insulin and without estrogen receptor cells, estradiol may not engender malignant cell growth, research has found.
The estradiol and cancer connection may be a result of more than just estradiol’s ability to cause cells to synthesize DNA and start proliferating. Scientists believe oxygen radicals are another key factor in estradiol becoming a true cancer risk. Studies have long indicated that free oxygen radicals can lead to cancer by damaging otherwise healthy cells; estradiol, according to studies, is dangerous because it can produce its own free oxygen radicals in ER-positive cells. While estradiol is mostly linked to breast cancer, it may also cause cancer of the uterus and the endometrium.
In normal amounts, estradiol and cancer are not linked. Estradiol is actually necessary and beneficial to women because it governs proper female development. For example, estradiol, which is made naturally in the female body every day, guides the development and maintenance of a woman’s uterus, breasts, and Fallopian tubes. This steroidal hormone also governs how fat is deposited on a woman’s body, guiding the shape of her figure. Along with two other forms of estrogen — estriol and estrone — estradiol helps regulate female menstruation and pregnancy.
Cancer risks arise when the presence of estradiol in the body is excessive; sometimes this is caused by medicines that contain estradiol from other animal sources. This therapeutic estradiol supplementation is often part of female hormone replacement therapy for conditions such as menopause. The hormone might also be present in some forms of birth control as well as certain cosmetics. These environmental and medical exposures raise the risk of women encountering the dangerous link between estradiol and cancer.
Also, since estradiol is occasionally used in some veterinary medicines, traces of the hormone can end up in some meats and milk, according to some medical reports. The link between elevated estradiol and cancer can be combated with anti-estrogen drugs. Doctors have found that certain steroidal antiestrogens can stop cancer growth from estradiol and even prevent it entirely.