Hormone replacement therapy (HRT) is a treatment that doctors prescribe to relieve symptoms of menopause. HRT can address the prevention of long-term diseases such as bone loss, the elevation of cholesterol, and obesity that can result from declining levels of the hormones estrogen and progesterone during and after menopause. (1)
There are also some forms of cancer that HRT can help prevent. This article will discuss what we know about HRT and how it may help prevent colon, endometrial, esophageal, and cervical cancer. (1-4)
Perimenopause and Menopause
Starting in your 30s or 40s, you will produce less estrogen, progesterone, and testosterone. This stage is called perimenopause. Eventually, your menstrual periods will stop with the continued drop of these hormones’ levels, and after 12 months without a period menopause will officially begin.
Perimenopause starts much earlier than you might expect. About 10% of women go through perimenopause before they turn 40 due to the estrogen, progesterone, and testosterone drop. Effective treatments are available to help relieve perimenopause symptoms including hot flashes, night sweats, anxiety, weight gain, mood swings, hair loss, wrinkles, low libido, painful sex, vaginal irritation, insomnia, UTIs, and depression (2-5). If the decreasing hormones are not corrected, women are at a greater risk of heart attack, diabetes, colon cancer, stroke, bone disease, dementia, and even suicide (2).
The good news is that peri- and menopause have been studied for over 60 years. Scientists have yet to identify a more effective remedy for perimenopause symptoms than HRT (2-4).
Overstated Risks of Taking HRT
HRT can help resolve the estrogen and progesterone deprivation that occurs with peri and menopause, but even though HRT is incredibly effective at relieving symptoms, only 10–15% of women in perimenopause will seek medical help to deal with the symptoms because of fear of the treatment and their physicians’ unwillingness to prescribe therapy. (1) Much of the hesitation is due to the fears of developing cancer when taking HRT. We don’t hear much about how HRT can reduce some forms of cancer.
One press release about HRT in 2002 has provided a world of misinformation about the safety of HRT. The initial WHI (Women’s Health Initiative) reported an overall increased risk of breast cancer, heart disease, stroke, and clots. The researchers later retracted and modified their statements, but the misinformation continues.
The WHI remains the largest randomized controlled trial of HRT. Most people don’t know that the 2002 research data was reevaluated, and the research results amended significantly to consider the many of the flaws in the initial study.
As a result of misunderstandings regarding the 2002 study, many women discontinued using HRT. HRT prescriptions in the United States rapidly decreased and a generation of women continue to suffer unnecessarily from profound menopause symptoms that can lead to chronic medical conditions if not treated.
One of the significant issues with the WHI study was that it only compared the use of one type of hormone replacement therapy called “conjugated equine estrogens” (CEEs) (derived from pregnant horse urine (!)) and “medroxyprogesterone acetate” (MPA) versus a placebo.
In the initial 2002 WHI study, the female patients were much older than women entering or in menopause. The average age of the women in the WHI study was 63 years old. Women that are 63 and have never had HRT before are not prescribed HRT today.
The design of the WHI led to an overestimation of the risks for women aged less than 60 years and at low risk of cardiovascular disease and breast cancer. The North American Menopause Society suggests starting HRT before 60 years or within 10 years of menopause onset. Menopause typically occurs at 51, but perimenopause can begin in a woman’s late 30s early 40s. The benefit-risk ratio is most favorable when you start HRT before postmenopause.
Much controversy remains about HRT despite the reanalysis of the WHI study and researchers properly breaking up the groups by age and the number of years they have been in menopause. Additionally, Winona’s HRT is entirely different from the synthetic estrogen the study used, derived from pregnant horse urine (!). The HRT Winona provides is made from yams and is safe, natural, and FDA approved.
Cancer and HRT – Why All the Fear?
Like going out in the sun or eating certain foods, there can be a small cancer risk with HRT, depending on many individual factors. Treatment should be individualized to identify the most appropriate dose, regimen, duration, and route of administration. 
Some types of cancer are known as ‘hormone-sensitive cancers.’ Hormones need to be balanced for all body systems to work correctly and to feel well. Hormones can affect everything from the beginning of menopause to metabolism and your mood. (2)
When hormones are not properly balanced, they can cause all sorts of problems. Some imbalances can cause minor symptoms, while others can create some very major issues, like tumors growing and spreading rapidly.
There are types of cancer called hormone-sensitive or hormone-dependent cancers. (2) Experts know that several different factors play a role in turning healthy cells cancerous. While estrogen doesn’t cause cancer there are a few types of cancer that can have accelerated growth when there are high levels of estrogen (6) If you have inherited the faulty breast cancer gene BRCA1 or 2, you will not be prescribed HRT.
Types of Cancer HRT May Help Prevent
Uterine & Endometrial Cancer
Endometrial cancer is a type of uterine cancer that involves the uterus lining. The risk of endometrial cancer was not increased by estrogen-progestin therapy in the study. (5) Women who take estrogen-only HRT and still have a uterus will be prescribed progesterone to protect them from uterine cancers.
Estrogen is used alone only in women who have had a hysterectomy.
Colorectal, Liver and GI Cancer
Studies in 2017 & 2018 state that HRT use is associated with a 10% decreased risk of all gastrointestinal cancers, particularly liver and colon cancers (2, 3, 4), a reduction in death from colorectal cancer, and all-cause mortality in HRT users. (3)
A possible explanation of the influence of HRT on colon cancer is that there are many estrogen receptors in the colon, and estradiol and progesterone may reduce the proliferation and increase cancer cell death (apoptosis) in colon tumors, probably through estrogen receptor activation. (4)
The use of estrogen plus progestin was associated with a significant decrease in the incidence of colorectal cancer. (1) In some studies, there was a 37% decrease in colon cancers in women who had taken HRT compared to women who did not. The use of oral HRT was associated with a 63% relative reduction in the risk of colorectal cancer. (4, 5, 6, 7)
In an extensive study of women, a reduction in cervical cancer risk among peri- and post-menopausal women using HRT was found, and the effect became stronger with a longer duration of use. (1)
Increasing duration of HRT use was associated with a reduced risk of oesophageal cancer. (8) A lag of 17 years has been reported among women developing esophageal cancer compared with men. That difference seems to coincide with menopause. There is an acceleration in the incidence of acid reflux in women after the age of 50. It has been hypothesized that a lack of estrogen in post-menopausal women may be responsible for this phenomenon. Balanced estrogen appears to protect the esophagus from acid reflux-induced damage that has been shown to lead to esophageal cancer.
Cancer and Inflammation
There are over 100 kinds of cancer that are often named for the organs and tissues where the cancer is formed. Some cancers arise from environmental exposures, while others are associated with damage to the DNA from internal factors. Inflammation is often associated with the development and progression of either type of cancer. (9)
The targeting of inflammation offers an attractive strategy to prevent and treat cancer. Tumor inflammation can be caused by infections, autoimmune diseases, obesity, tobacco smoking, and asbestos exposure, increasing cancer risk and stimulating malignant cell growth. Inflammation can trigger the malignant growth of cancer and result in immunosuppression, providing a dangerous combination. (9)
Balanced estrogen levels have been shown to have significant anti-inflammatory properties. (9) Estrogen replacement in the form of HRT may therefore potentially protect against and/or slow the rate of tumor growth. (9) Many studies continue to contribute to the reinforcement of inflammation-targeting cancer prevention and treatment, and it is an exciting field of cancer prevention. (10) You can also visit our anti-aging and wellness center site to learn more about these matters.
- Simin J., Tamimi R., Lagergren J., Adami H.-O., Brusselaers N. Menopausal hormone therapy and cancer risk: An overestimated risk? J. Cancer. 2017;84:60–68. doi: 10.1016/j.ejca.2017.07.012.
- Symer M.M., Wong N.N., Abelson J.J., Milsom J.J., Yeo H.H. Hormone Replacement Therapy and Colorectal Cancer Incidence and Mortality in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Colorectal Cancer. 2018;17:e281–e288. doi: 10.1016/j.clcc.2018.01.003.
- Williams C., DiLeo A., Niv Y., Gustafsson J.-Å. Estrogen receptor beta as target for colorectal cancer prevention. Cancer Lett. 2016;372:48–56. doi: 10.1016/j.canlet.2015.12.009.