Antiestrogen Vs Estrogen Blockers
Both antiestrogen and estrogen blockers aim to slow or stop the progression of breast cancer. The two different treatments dont work the same way, though.
Tamoxifen, a widely used estrogen blocker, stops estrogen from affecting breast tissue. Aromatase, an antiestrogen therapy, lowers the production of estrogen in postmenopausal women.
Tamoxifen is well known and widely used as chemoprevention a medication to prevent disease for women with a high risk of developing invasive breast cancer, according to
, researchers found that when postmenopausal women in the increased risk category took tamoxifen for 5 years, it lowered their risk of developing invasive breast cancer by 50 percent.
A 2017 study found that use of tamoxifen and antiestrogen medications led to a 50 to 65 percent decrease in breast cancer development in high risk groups.
Both estrogen blockers and antiestrogen therapies are effective, but there are side effects, too. Its important to weigh the benefits and risks with your care team before deciding on this course of action.
Can A Person Lower Their Breast Cancer Risk
If a person decides to take HRT, they can ask for a lower-dose formula. They can also discuss with a doctor how to take it for the shortest possible time.
BreastCancer.org notes that a person can take certain steps to reduce their risk of developing breast cancer whether they use HRT or not.
They recommend that a person:
- exercise regularly
- quit smoking, if applicable
- limit their intake of alcohol
It is also important to achieve and maintain a healthy weight. This is because having more fat tissue can raise a persons estrogen levels, and as a result, increase the chance of developing breast cancer.
The ACS adds that a person at higher risk for breast cancer may benefit from taking additional steps, such as:
- getting closer monitoring
- seeking genetic testing and counseling
- getting preventative surgery
For those with a high risk of developing breast cancer, an oncologist may prescribe medications such as tamoxifen and raloxifene.
Practical Use Of Attributable Risks And Benefits In Decision Making
Short-term use of ERT/HRT for menopausal symptoms. Use of ERT or HRT for less than 2 yr causes only a negligible increase in risk of breast cancer in a 50-yr-old woman . Consequently, a woman could be encouraged to take short-term ERT or HRT for menopausal symptoms without a great deal of concern regarding risk of breast cancer.
Long-term use of ERT/HRT to prevent heart disease or osteoporosis. The longer a woman takes estrogen, the greater is her risk of developing breast cancer attributable to this hormone. The attributable risk associated with estrogen alone, when taken by the average 50-yr-old woman for 10 yr, is a 1 in 397 increase in the chance of getting a breast cancer. For 60-yr-old women, the respective risk is 1 in 286. If we accept the data of Schairer et al. as valid, the RR of breast cancer increases by 8% per year with use of an estrogen plus a progestin. Using these data, we may calculate that, for the 50-yr-old taking HRT for a 10-yr period, the breast cancer risk attributable to hormonal therapy would be 1 in 50. For the 60-yr-old, the risk increases to 1 in 36.
Bioassay Of Clampede2 On Uterine Weight
Our various strategies to examine the ER-independent effects of E2 critically depended on complete blockade of any residual ER activity resulting from a truncated ER or from low levels of ER. Measurement of uterine weight provided a robust bioassay of E2 to determine whether complete blockade was achieved. We measured uterine weight after at least 2 months of E2 exposure under each experimental condition . In the ERKO castrate animals, E2 stimulated uterine weight to 18% of that observed in ER+/+/Wnt-1 animals, an effect resulting from a biologic effect of the truncated 56KD receptor . Fulvestrant completely blocked the residual ER responsiveness in the ERKO/Wnt-1 animals. Uterine weight fell to 7 ± 1 mg in the animals receiving 240 pg/ml E2 plus fulvestrant, a uterine weight similar to that observed in castrate animals . In aggregate, these data demonstrated that fulvestrant was capable of completely abrogating the effects of residual ER activity in ERKO animals.
Uterine wet weights in ER+/Wnt-1 and ERKO/Wnt-1 animals. Shown are mean weights of the uterus under various conditions. Data from ER-animals were pooled from different experiments . 17-E2/ovx: castrate animals receiving 17-OH-E2 to produce plasma levels of 240 pg/ml . Statistical analysis: ER+ groups: compared to intact , compared to ovx , compared to ovx + E2 ; ERKO groups: compared to intact , compared to ovx , compared to ovx + E2 with all p-values less than 0.001.
Estrogen And Breast Cancer
The molecular form for one type of estrogenA female sex hormone that is primarily produced by the ovaries. Its primary function is to regulate the menstrual cycle and assist in the production of secondary sex characteristics such as breasts. It may even play a role in the production of cancer cells in the breast tissue. called estriol. High levels of estrogen in the body have been shown to be a risk factorAnything that increases or decreases a persons chance of developing a disease. for breast cancer.
High estrogen levels in the body are believed to dramatically increase our risk of breast cancer. It is therefore worth understanding what estrogen is and how you can control your estrogen level at the same time as other;breast cancer risk factors.
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Controlling Estrogen Level To Combat Breast Cancer
Regardless of exactly how estrogen causes increased breast cancer risk, it is worth keeping low estrogen levels in your body because this is shown to potentially reduce your breast cancer risk and is an excellent natural remedy for hormone-receptor-positive breast cancers that do arise.
- Stop smoking
- Reduce saturated and trans fats
- Reduce usage or eliminate hormone replacent therapy during and after menopauseThe end of a womans menstrual cycles, defined as 12 consecutive months of no menstrual periods.
- Choose to breastfeed, if possible
All of the above factors contribute to reducing estrogen levels in the body. Controlling them helps decrease your risk for breast cancer and gives you a healthier lifestyle in general.
Of course, there are also a number of factors relating to estrogen which cannot be controlled. Women who start their period early or begin the menopause late are believed at higher risk of developing breast cancer, for example. So are those who have children late or dont have any at all. This is possibly because these women are exposed to more estrogen overall in their lifetimes. On the flipside, each time you get pregnant for a prolonged period, you effectively decrease the number of menstrual cycles and hormone fluctuations in your lifespan, reducing the breast cancer risk.
Other Factors Which Influence Decision Making
The two most recent studies of HRT and breast cancer risk suggest that only thin patients experience an increased risk of breast cancer from either estrogen alone or the combination of estrogen and a progestin . When limiting analysis to thin women, only those taking HRT long term had a statistically significant increase in breast cancer risk. Obese women did not have an increased risk of breast cancer attributable to HRT. A family history of breast cancer, early age of menarche, late age of child bearing, a high-fat diet, obesity, increased breast density on mammograms, and certain benign breast lesions increase the underlying risk of developing a breast cancer. Finally, several studies suggest that the breast cancers that develop in women receiving HRT are less aggressive in type and are associated with a better prognosis .
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Box 1 Cumulative Evidence To Support Low Dose Estrogen
Historical use of estrogens to treat breast cancer.
Physiologic estrogen as an antitumor agent in SERM-resistant breast cancer models in vivo.
Estrogen-induced apoptosis in estrogen-deprived ER-positive cell lines in vitro.
A current evaluation of estrogen to treat acquired antihormone resistance in metastatic breast cancer.
The extrapolation of the concept that physiologic estrogen kills breast cancer cells to adjuvant antihormone therapy.
Estrogen And Breast Cancer Risk
Estradiol,;and possibly estrone, increase the risk of developing breast cancer. And a lower level of these estrogens throughout a woman’s lifetime is associated with a lower risk of developing breast cancer.
Factors such as pregnancy and breastfeeding alter estrogen levels in ways that are believed to have a protective effect. Having a first child before the age of 30, having more children, and breastfeeding are all associated with a lower risk of breast cancer due to the reduced production of estrogens during pregnancy and lactation .
Because oral contraceptives and hormone replacement therapies contain estrogen, there is a small potential they may increase the risk of breast cancer for some women.
While we know that estrogen receptor-positive breast cancers are worsened by estrogen, other breast cancer types typically are also more common among women who have had a higher lifetime exposure to estrogen.
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Monitoring Your Estrogen Levels
No matter what stage of life youre in, talk with your healthcare provider. Its important to monitor hormones, especially if youre having symptoms of high estrogen.
Estrogen levels are easy to check. Labs can report on total estrogen. They can also break down results by estrogen type. This will let you take a closer look at your estradiol.;
Its also good to check progesterone. Your levels may be too low and contributing to estrogen dominance. Or, your progesterone could be too high. And, you dont want that, either. About 65% of estrogen-receptor positive breast cancers are also progesterone-receptor positive . That means they can grow by attaching to progesterone, too.
Do The Benefits Of Hrt Outweigh The Risk
Hormone replacement therapy is an effective treatment for relieving hot flashes from menopause. But the known link between hormone therapy and increased breast cancer among risks has discouraged many women and their doctors from choosing or recommending this treatment.
The type of hormone therapy , as well as the woman’s individual characteristics, risk factors, and severity of menopause symptoms, should be considered when weighing the risks and benefits of HRT. The decision to use hormone therapy after menopause should be made by a woman and their health care provider after weighing all of the potential risks and benefits .
The known association between HRT and breast cancer has prevented many breast specialists from recommending it for breast cancer survivors. Unfortunately, many women experience menopause symptoms after breast cancer treatment. Some forms of chemotherapy may also cause early menopause in premenopausal women.
In the past, doctors may have offered HRT after breast cancer treatment because there weren’t clearcut studies showing any harm. However, early in 2004, a study was stopped early after showing that cancer survivors on HRT were more likely to develop a new or recurrent breast cancer. Doctors now feel it is too risky to treat breast cancer survivors with HRT.
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The Truth About Estrogen Dominance And Breast Cancer
Solid medical science and clinical studies have established that an underlying and untreated condition of “estrogen dominance” significantly increases your breast cancer risk: women who develop breast cancer have higher estrogen levels than women without breast cancer.
Some studies have also shown that women who had been treated for breast cancer, and who continued to have high estrogen levels, had a return of the disease sooner than breast cancer survivors with lower estrogen levels.;The reason is that one of estrogen’s functions in the body is to foster cell growth, or “cell proliferation.” At a cellular level, unchecked cell growth can be a precursor for cancer.;
New Research Again Links Increased Breast Cancer Risk To Longer Use Of Hormone Therapy
The link between hormone therapy and breast cancer has been recognized for years. But an analysis published Aug. 29, 2019, in The Lancet has added some additional information to the discussion. The analysis looked at 58 studies that included information on the type and timing of hormone use in individual women, and their body mass index. Researchers began gathering the studies in 1992 and continued until 2018.
We asked Dr. Wendy Chen, an assistant professor of medicine at Harvard Medical School, to help us sort through both the old and new information on hormone use and breast cancer and what it means for women considering starting hormone therapy.
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What Do Estrogen Blockers Do For Females
Estrogen blockers are chemicals that essentially prevent cancer cells in females from getting the hormones they need to grow, like estrogen.
Many breast cancers are sensitive to hormones like estrogen and respond to this type of treatment. This accounts for 70 to 80 percent of all breast cancers, or 2 out of 3.
When breast cancers sensitive to hormones cant get estrogen they need to grow, they may shrink in size or be unable to grow much at all.
However, a smaller number of breast cancers are insensitive to hormones, meaning they dont benefit from antiestrogen therapy and require different treatments.
Blood Estrogen Levels And Breast Cancer Risk
This summary table contains detailed information about research studies. Summary tables are a useful way to look at the science behind many breast cancer guidelines and recommendations. However, to get the most out of the tables, its important to understand some key concepts. Learn how to read a research table.
Introduction: Estrogens are natural hormones important for sexual development and other body functions. Before menopause, they are produced mainly in the ovaries. After menopause, they are produced mainly in fat tissue.
Women have different sources of estrogen before and after menopause. So, its important to look at studies of estrogen and breast cancer risk by menopausal status.
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Learn More With Overcoming Estrogen Dominance
The body has an amazing ability to heal. We just need to give it the right resources.
In Overcoming Estrogen Dominance, my goal is to empower and give you the tools to take control of your hormones and health.
More than 70% of women experience estrogen dominance. The symptoms range from lumpy and fibrocystic breasts to thyroid nodules, hot flashes, fibroids, uterine polyps, painful, heavy or irregular periods to infertility and miscarriages, from mood swings to insomnia, weight gain to fatigue.
So many women have experienced the pain and frustration that comes when they feel their symptoms and complaints are dismissed or minimized. This is particularly true for women who are experiencing the symptoms of hormone imbalance. Even when doctors do offer treatment, its typically in the form of prescription medication or invasive surgical procedures.
In Overcoming Estrogen Dominance, I hope to show that those extreme interventions are often unnecessary, and to give women a roadmap to reverse estrogen dominance using food, herbs, supplements and natural protocols to rebalance hormones.
To get your copy of Overcoming Estrogen Dominance, go here.
Previous Breast Cancer Or Lump
If you have previously had breast cancer or early non-invasive cancer cell changes in breast ducts, you have a higher risk of developing it again, either in your other breast or in the same breast.
A;benign breast lump does not mean;you have breast cancer, but certain types of breast lumps may slightly increase your risk of developing cancer.
Some benign changes in your breast tissue, such as;cells growing abnormally in ducts;, or;abnormal cells inside your breast lobes , can make getting breast cancer more likely.
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Relationship Between Cell Proliferation And Breast Cancer
A general theory of carcinogenesis holds that agents that increase the rate of cell proliferation can enhance the development of new genetic mutations . Mutations are thought to be necessary for the process of initiation of cancer. Once mutations are present, they need to be propagated by cell replication, a process considered to be responsible for tumor promotion. Estrogens are known to enhance the rate of cell proliferation in glandular tissue of the breast and, thus, could potentially act both in the initiation and promotion of breast cancer.
What Is Unique About The Young Mammary Gland That Makes It So Susceptible To Cancer Induction And Protection
The fact that two crucial reproductive events, menarche and young age at parity, have the greatest effect on lifetime breast cancer risk suggests that the young mammary gland represents a crucial window in tumorigenic susceptibility. Why this is the case is less clear. Based on the epidemiological evidence for this, a few hypotheses have been generated, but again few have been tested experimentally, and this work is largely restricted to rodent models.
Evidence From The Historical Use Of Estrogens To Treat Metastatic Breast Cancer
The application of high-dose estrogen therapy for the treatment of metastatic breast cancer was the first use of a chemical therapy to treat any cancer successfully . Estrogen therapy became the standard of care to treat metastatic breast cancer in postmenopausal patients until the introduction of tamoxifen , a nonsteroidal antiestrogen . Tamoxifen became the gold standard for the treatment of ER-positive breast cancer for the next 20 years. Estrogen was all but abandoned as a treatment option, but Ingle and colleagues completed a provocative trial of tamoxifen versus the synthetic estrogen diethylstilbestrol in metastatic breast cancer . Responses were equivalent with fewer side effects with tamoxifen, but a re-analysis years later demonstrated that survival was significantly improved with DES .
Towards the end of his distinguished career, Professor Sir Alexander Haddow FRS reflected on the remarkable responses noted with estrogen in some tumors, often when treatment was more than a decade past menopause: The extraordinary extent of tumour regression observed in perhaps 1% of post-menopausal cases has always been regarded as of major theoretical importance, and it is a matter for some disappointment that so much of the underlying mechanisms continues to elude us.