Conflicting Role of Estrogen: A Villain and A Possible Savior in Breast Cancer

What is Estrogen?

Estrogen is essential for normal sexual development and functioning of female organs important for childbearing like the ovaries and uterus. It also helps regulate the woman's menstruation cycle. It stimulates the development of the secondary female sex characteristics: rounded breasts and hips and pubic hair. It also helps maintain the heart and healthy bones.

This hub is in connection to my Breast Cancer Awareness: Lumpectomy VS. Mastectomy hub. Please check that hub, too.

Estrogen - Cause and Treatment of Breast Cancer?

One major factor in the cause of breast cancer is estrogen. This is a shocking thought to us, women. The same hormone (estrogen) that makes our hair thick, makes our skin soft, fills out our hips and breasts and makes our waists curve also cause tumors and cancers on breasts.


Excessive secretion of estrogen may result in the formation of breast tumors and cancers, as well as ovarian cysts or tumors of the uterus.


In part, breast cancer has the highest rate in developed countries, scientists say, because with better nutrition we reach menstruations earlier and menopause later, thus allowing estrogen to course through our bodies for that much longer.


The bright side to this is that estrogen can now be used as breast cancer treatment. The most exciting development is the introduction of a new class of drugs called aromatase inhibitors, which are used by postmenopausal women against late-stage tumors and may prove more effective when tumors are diagnosed early.

Tamoxifen Molecule

Breast Cancer Drugs


Tamoxifen(Nolvadex®) is routinely given to woman who has high risk for recurring tumors. This was hailed seven years ago as the first drug approved for reducing the risk of getting breast cancer (rather than just treating it). It is far from perfect because it increases the risk of uterine cancer and fatal blood clots.


Raloxifene Molecule

Raloxifene (EVISTA®) which was originally designed to prevent osteoporosis, also appears to block breast cancer. It seems to have fewer side effects, and the study comparing the two drugs: tamoxifen and raloxifene won’t be available until this year 2009.


Tamoxifen and raloxifene are known as “designer estrogens.” They work as substitutes of the body’s natural estrogen on the surface of breast cancer cells, thus preventing tumor to develop.

Researchers are studying on who will most likely benefit from any of these “designer estrogens.” It turns out that raloxifene is the most effective for the postmenopausal women who have naturally high levels of estrogen. Tamoxifen, on the other hand, offers little or no benefit to women who carry the BCRA1mutation, which is one of two genetic mutations known to cause an inherited form of breast cancer. And women who carry BRCA2 in their gene, tamoxifen can lower their risk of breast cancer.

Women who are taking tamoxifen should continue doing so. Doctors will almost certainly have more drugs to choose from in the future; they may use designer estrogens and aromatase inhibitors in sequence to try to keep breast cancer cells off-balance.


Aromatase inhibitors

Aromatase inhibitors block the action of an enzyme that produces estrogen. Studies suggest that these drugs can shrink tumors before surgery and may prevent breast cancer from recurring. These drugs could one day replace tamoxifen and raloxifene.

Of course, the ultimate goal for the researchers is to keep breast cancer from taking hold in the first place, and estrogen will play a role in achieving that. The researchers have begun the test to temporarily suppress the body’s natural estrogen and they provide birth control drugs along with protection from breast cancer. This can be accomplished by combining ovulation-stopping drug with tiny doses of female hormones to protect tissues like bone and brain.

A pilot study has been conducted at the University of Southern California in women with a family history on breast cancer. It showed that a dosage regimen –ovulation-stopping drug and tiny doses of female hormones, reduced breast density, making mammogams easier to read. And there is an added benefit to it; the treatment cut their menstrual cycle to three times a year.

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Comments 5 comments

Peaceful life profile image

Peaceful life 5 years ago from Las vegas

a good peace of information, nice work


beth811 profile image

beth811 5 years ago from Philippines Author

Ingenira - I'm sorry to hear about your condition. Best wishes to you.

Thank you for your comment.


Ingenira profile image

Ingenira 5 years ago

Wow, these are really scientific information from medical field. I have read quite a bit on estrogen myself since I suffer from endometriosis. I have to keep the estrogen level low, and I do it with special endo diet. It works for me.


beth811 profile image

beth811 7 years ago from Philippines Author

Thanks for reading this hub, Ambition.


Ambition398 profile image

Ambition398 7 years ago

What a great - and timely - hub.

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