Estrogen Therapy And Cancer Risk
Endometrial cancer
In women who still have a uterus, using systemic ET has been shown to increase the risk of endometrial cancer . The risk remains higher than average even after ET is no longer used. Although most studies that showed an increased risk were of women taking estrogen as a pill, women using a patch or high-dose vaginal ring can also expect to have an increased risk of endometrial cancer.
Because of this increased cancer risk, women who have gone through menopause and who still have a uterus are given a progestin along with estrogen. Studies have shown that EPT does not increase the risk for endometrial cancer.
Long-term use of vaginal creams, rings, or tablets containing topical estrogen doses may also increase the levels of estrogen in the body. Its not clear if this leads to health risks, but the amounts of hormone are much smaller than systemic therapies.
Breast cancer
ET is not linked to a higher risk of breast cancer. In fact, certain groups of women taking ET, such as women who had no family history of breast cancer and those who had no history of benign breast disease, had a slightly lower risk of breast cancer.
Ovarian cancer
The WHI study of ET did not report any results about ovarian cancer.
To put the risk into numbers, if 1,000 women who were 50 years old took estrogen for menopause for 5 years, one extra ovarian cancer would be expected to develop.
Colorectal cancer
Lung cancer
ET does not seem to have any effect on the risk of lung cancer.
Confirmed: A Link Between Breast Cancer And Hormone Therapy
Breast cancer incidence parallels estrogen-progestin use among menopausal and postmenopausal women
Researchers at the Kaiser Permanente Center for Health Research in Portland, Ore., concluded there is definitely a link between breast cancer and the use of menopausal hormone therapy, particularly estrogen-progestin treatment combinations. Since 1990, “breast cancer rates dropped in parallel with hormone use just as it rose in parallel to it,” says oncologist Andrew Glass, lead author of the study published in the Journal of the National Cancer Institute.
Glass and his colleagues reviewed the medical histories of 7,386 women diagnosed with invasive breast cancer between 1980 and 2006. They found that breast cancer incidence rose 25 percent from the early 1980s to the early 1990sa period when an increasing number of women were getting mammograms and also undergoing hormone therapy to control menopause symptoms and prevent chronic disease. Glass acknowledges that the jump in breast cancer could be attributed to more women getting mammograms, because the test can find cancers that might otherwise go undetected until the disease has progressed.
“It’s not exact cause and effect, but it’s as close as you can be in epidemiology,” Glass says. “There is no other explanation for what we’ve found.”
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There is still a lot of evidence to suggest that HRT is safe and effective, and current clinical guidelines recommend it as an appropriate treatment for some women going through menopause. Nevertheless, it is important that clinical guidelines are evidence-based, and that this study is taken into account as clinical guidelines are updated and developed, he said. We would urge patients not to panic as a result of this research, and to continue taking HRT as it has been prescribed to them and we would urge prescribers to do so as normal, until clinical guidelines recommend otherwise.
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Estrogen Linked To Bone Health
A healthy level of estrogen in your body builds and maintains strong bones. However, if youve had chemotherapy or if youre taking estrogen-suppression medication after treatment for breast cancer, your estrogen levels will be low. Guard your bone health by understanding how estrogen affects your bones.
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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Estrogen Receptor Blockers Estrogen Receptor Blocker Drugs Attach Directly To And Block The Estrogen Receptors On Cancer Cells So That The Cancer Cells Cant Use Estrogen They Do Not Affect The Level Of Estrogen In The Body Estrogen Receptor Blockers Are Also Called Selective Estrogen Receptor Modulators
Tamoxifen
Tamoxifen is the most commonly used anti-estrogen drug. It is used in post-menopausal and premenopausal women. Tamoxifen is given by mouth as a pill.
Tamoxifen is the hormonal therapy drug used most often to lower the risk that DCIS or LCIS will lead to an invasive breast cancer.
Tamoxifen very slightly increases the risk for uterine cancer, deep vein thrombosis and stroke. Doctors will carefully weigh these risks against the benefits of giving this drug before they offer it to women who have a personal or a strong family history of these conditions. Usually the benefits of taking tamoxifen outweigh these risks.
Fulvestrant
Fulvestrant is an anti-estrogen drug that reduces the number of estrogen receptors on breast cancer cells. It is given as an injection into the muscles of the buttocks.
Fulvestrant is used in post-menopausal women if the breast cancer has grown after they were treated with tamoxifen. It is also used in postmenopausal women with locally advanced or metastatic breast cancer that have never been treated with hormonal therapy.
Does Hrt Increase The Risk Of Womb Cancer
The risk of womb cancer depends on the type of HRT.
Oestrogen-only HRT increases the risk of womb cancer. The longer this type of HRT is used, the bigger the risk. Thats why oestrogen-only HRT is usually only offered to those who have had their womb removed as they have no risk of womb cancer to begin with.
Combined HRT can reduce womb cancer risk. But combined treatment causes the biggest increase in breast cancer risk. So, its important to talk to your doctor about the balance of possible benefits and risks for you.
Similar to oestrogen-only HRT, tibolone also increases the risk of womb cancer.
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What Is A Hormone Receptor
In breast cancer, hormone receptors are the proteins located in and around breast cells. These receptors signal cells both healthy and cancerous to grow. In the case of breast cancer, the hormone receptors tell the cancer cells to grow uncontrollably, and a tumor results.
Hormone receptors can interact with estrogen or progesterone. Estrogen receptors are the most common. This is why ER-positive is the most common form of breast cancer.
Some people are diagnosed with progesterone receptor-positive breast cancer. The key difference is whether cancerous cells are getting growth signals from estrogen or progesterone.
Testing for hormone receptors is important in treating breast cancer. In some cases, there are no hormone receptors present, so hormone therapy isnt a good treatment option. This is called hormone receptor-negative breast cancer.
According to
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Additional And Sensitivity Analyses
To assess possible age related differences in risks associated with exposures to hormone, we performed additional analyses for different age categories at the index date: 50-59 years, 60-69 years, and 70-79 years. We ran another subgroup analysis for women in three different BMI groups: less than 25, 25 up to 30, and 30 or more. In this analysis, we included only controls in the same body mass category as their matched case.
For the main analysis, we considered women to have recently used HRT if they had a prescription between one and five years before the index date. The risk associated with HRT has been found to decrease rapidly after discontinuation,20 so we needed a measure showing excess of risk for the most recently exposed women. To assess this, we repeated the analysis, defining recent use as exposure between one and two years before the index date.
The main analysis was run on women aged 50 to 79, which may include some premenopausal and perimenopausal women who have a higher risk of breast cancer.21 To deal with this and provide comparability of our results with those of a meta-analysis,11 we also ran an additional analysis restricting our sample to women aged 55 to 79.
We used Stata v16 for all analyses. A 1% level of statistical significance was used to allow for multiple comparisons. To facilitate comparison with other studies, however, we present the results as odds ratios with 95% confidence intervals.
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Postmenopausal Estrogen And Risk Of Breast Cancer: What Is The Real Story
I am responding to an article in the January 25, 2020, issue of The ASCO Poston the conclusion of the 19-year follow-up on the Womens Health Initiative presented by Rowan T. Chlebowski, MD, PhD, at the 2019 San Antonio Breast Cancer Symposium: Postmenopausal estrogen administration does not increase the risk of breast cancer after all, he said, and, in fact, it may decrease the risk the real culprit is estrogen combined with progesterone. Given that the WHI was largely responsible for frightening millions of women and their physicians into believing that estrogen causes breast cancera conclusion that it has been modifying and retracting over the past decadeit behooves us to try to understand what is really going on.
The current WHI update report that postmenopausal estrogen does not increase the risk of breast cancer is reinforced by other long-established findings in the medical literature, such as the 70% decrease in breast cancer risk associated with a full-term pregnancy before the age of 18 the lack of benefit resulting from an abortion at the time of breast cancer diagnosis and the safety of pregnancy after treatment of breast cancer, even among estrogen receptorpositive women.
Remarkable Analysis
This remarkable analysis should have been incorporated into the 19-year interpretation of the results presented in San Antonio and published in The ASCO Post article.
Avrum Bluming, MD
Emeritus Clinical Professor of Medicine
REFERENCES
The Million Women Study2124
In the UK all women aged 5064 years are invited to undergo screening mammography at 3-year intervals. From May 1966 to December 2001 the MWS investigators sent letters and questionnaires to women invited to attend. Follow-up questionnaires were sent 23 years after recruitment. The women were followed for breast cancer incidence and mortality in National Health Service Central Registries.
Below, except where otherwise stated, all 95% confidence intervals around the relative risk estimates excluded 1.0, and for convenience they are omitted.
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Menopausal Hormone Therapy And Cancer Risk
For decades, women have used hormone therapy to ease symptoms of menopause, such as hot flashes and sweating. This is called menopausal hormone therapy, and you may see it abbreviated as HT or MHT. You may also hear it described as hormone replacement therapy , postmenopausal hormone therapy , or postmenopausal hormones .
In the past, many doctors and their patients believed that MHT didnt just help with hot flashes and other symptoms it had important health benefits. But well-conducted studies have led many doctors to conclude that the risks of MHT often outweigh the benefits.
This information covers only how MHT can affect a womans risk of getting certain cancers. It does not cover other possible risks of MHT such as heart disease or stroke.
You can use this information when you talk to your doctor about whether MHT is right for you.
Does Hrt Cause Weight Gain
Contrary to popular belief, HRT does not cause weight gain. Changes in weight are typically from menopause and other lifestyle factors. Any noticeable weight gain is usually just bloating and swelling.15
For some women, the benefits may outweigh these side effects. Talk to your doctor to see whats right for you. As always, dont be afraid to express any concerns or hesitations.
References
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Alternatives To Hrt For Protecting Your Bones From Osteoporosis
HRT is no longer recommended for treatment of osteoporosis due to its risks and available alternative options. Bisphosphonate medications are generally recommended to treat osteoporosis instead. Other medications that may be considered are teriparatide, denosumab, or selective estrogen receptor modulators . SERMs are a newer class of drugs, similar to estrogen, that protect against osteoporosis by increasing bone density, while also protecting against the development of breast cancer.
Evista is a widely used SERM that has been shown to increase bone growth and density and reduce the risk of breast cancer. Unfortunately, it does not relieve symptoms of menopause such as hot flashes and may actually worsen them. It is primarily used in women who are at high risk for developing breast cancer or for those who cannot tolerate other medications used to treat osteoporosis.
Additional steps you can take to prevent and/or treat osteoporosis include:
- Performing weight-bearing exercises
Risk Factors You Can Change
Weight. Being overweight after menopause increases your odds.
Drinking alcohol.Alcohol is linked to breast cancer. Compared with nondrinkers, women who drink one alcoholic drink a day have a very small increase in risk, and those who are moderate drinkers have about a 20% higher risk.
Hormone replacement therapy . Long-term use of estrogen and progesterone increases the risk of breast cancer. This risk seems to go away if youve stopped using them for 5 years or longer.
Being inactive. Your odds go up if you donât exercise.
Reproductive history. Having your first child after age 30 or never having a full-term pregnancy puts you at higher risk. So does not breastfeeding.
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How Is Hormone Therapy Used To Treat Breast Cancer
There are three main ways that hormone therapy is used to treat hormone-sensitive breast cancer:
Adjuvant therapy for early-stage breast cancer:Tamoxifen is FDA approved for adjuvant hormone treatment of premenopausal and postmenopausal women with ER-positive early-stage breast cancer, and the aromatase inhibitorsanastrozole, letrozole, and exemestane are approved for this use in postmenopausal women.
Research has shown that women who receive at least 5 years of adjuvant therapy with tamoxifen after having surgery for early-stage ER-positive breast cancer have reduced risks of breast cancer recurrence, including a new breast cancer in the other breast, and reduced risk of death at 15 years .
Until recently, most women who received adjuvant hormone therapy to reduce the chance of a breast cancer recurrence took tamoxifen every day for 5 years. However, with the introduction of newer hormone therapies , some of which have been compared with tamoxifen in clinical trials, additional approaches to hormone therapy have become common .
Some premenopausal women with early-stage ER-positive breast cancer may have ovarian suppression plus an aromatase inhibitor, which was found to have higher rates of freedom from recurrence than ovarian suppression plus tamoxifen or tamoxifen alone .
Men with early-stage ER-positive breast cancer who receive adjuvant therapy are usually treated first with tamoxifen. Those treated with an aromatase inhibitor usually also take a GnRH agonist.
Use Of Hormone Replacement Therapy And Risk Of Breast Cancer: Nested Case
- Accepted 17 September 2020
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Is It Safe For Women Who Have Had A Cancer Diagnosis To Take Mht
One of the roles of naturally occurring estrogen is to promote the normal growth of cells in the breast and uterus. Some cancers also use estrogen to promote their growth. Thus, it is generally believed that MHT may promote further tumor growth in women who have already been diagnosed with breast cancer. However, studies of MHT use in breast cancer survivors have produced conflicting results, with some studies showing an increased risk of breast cancer recurrence and others showing no increased risk of recurrence .
Does Estrogen Really Cause Breast Cancer
The short answer? No, it does not! Mis-information and outdated studies are what guides many to believe that estrogen can raise the risk of breast cancer in women. The questions we should be asking are: what does new research tell us and what do we know now?
Lets talk about a recent book about womens health: Estrogen Matters: Why Taking Hormones in Menopause Can Improve Womens Well-Being and Lengthen Their LivesWithout Raising the Risk of Breast Cancer. The author is Avrum Bluming, an oncologist with more than 20 years of experience treating cancer.
Dr. Bluming has gone through the many years of research including clinical research at his own practice and hes come up with some important conclusions. The number 1 thing he has said is that estrogen does NOT cause breast cancer. I think many women are fearful of this, and therefore avoid the use of hormone replacement therapy.
He has also found that estrogen prevents heart disease. Heart disease or cardiovascular disease is a leading cause of death in women. I think its important that we understand the role of estrogen and preventing it and prolonging our lives.
where I discuss the importance of hormones in regard to heart disease.
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