Before the results of the Women’s Health Initiative (WHI) were published in 2002, we would frequently hear from women who were worried that the use of hormone replacement therapy (HRT) might be linked to breast cancer. In many cases, their physicians reassured them that there was no connection and that HRT was not only safe but essential for bone strength and heart health.
Here is a letter we published in our newspaper column on October 26, 1998, years before the WHI data were released:
Q. I am debating hormone replacement therapy. My doctor is very enthusiastic about Prempro, and says it will prevent osteoporosis and heart disease. My grandmother was crippled by spinal fractures so this is of concern.
I do worry about side effects such as breast cancer. My doctor downplays the danger but I would like to know as much as possible about all my options, including herbs, diet and exercise.
Then there was this from an irate husband:
“My wife is so angry at her physician that she can barely bring herself to schedule a visit. For years she was told to take Premarin and Provera. When reports surfaced that there might be “a problem with breast cancer, she asked her doctor about this risk. He repeatedly reassured her that there was nothing to worry about. Hormones were so safe, he claimed, that his own wife was taking them.”
The Women’s Health Initiative was stopped prematurely 11 years ago because of evidence suggesting that the combination of estrogen and progestin not only increased the risk of breast cancer but also elevated the likelihood of heart attacks and strokes. Initially, the medical community greeted this news with a great deal of skepticism. Here is an example of what some women faced:
Doctor Fires Patient Over HRT
“I have been on hormone replacement therapy for ten years, and my doctor has always been a strong proponent of HRT. I have been uncomfortable taking this and have asked about its safety in the past. He maintained that the news media only picks out the negative results of studies and ignores the positives, and he has always convinced me to continue taking HRT.
“I called my doctor’s office to discuss the recent warnings and learned that he has not changed his position concerning the benefits of HRT. I informed the nurse that I was uncomfortable taking the hormones and was going to discontinue taking them. I was then shocked to receive a letter from my doctor saying he can no longer treat me since I don’t agree with his philosophy on these drugs.
“I’ve gone to this doctor for years, and he initially prescribed HRT for me ten years ago. I didn’t realize that if I opted to stop, he would refuse to treat me. I am in excellent health and have no medical reason to take hormones other than menopause. Is it acceptable for a doctor to respond in this manner, by ‘dumping’ a patient? I thought it was the patient’s choice whether or not to take HRT.”
Although initially many HRT proponents tried hard to poke holes in the data, most physicians eventually accepted that there was indeed an increased risk of cancer as well as cardiovascular disease associated with estrogen and progestin therapy.
But over the years the doubters began to gain ground. Last year some researchers described HRT concerns as “mass fear” and “hysteria.” These experts maintained that the benefits of hormone replacement therapy outweighed the risks. If there was an increased risk of breast cancer, they claimed, it was extremely small and may have only represented an earlier diagnosis rather than a true cancer increase. They also suggested that if HRT were linked to breast cancer, any tumors would be easier to treat and less dangerous than “normal” breast cancer.
A brand new analysis from the Women’s Health Initiative may silence these apologists once and for all. On March 29, 2013, a study was published in the Journal of the National Cancer Institute that establishes unequivocally that HRT is indeed linked to an increased risk of breast cancer. The authors concluded:
“In summary, estrogen plus progestin use is associated with increased breast cancer incidence, especially when its use is initiated close to menopause. Because prognosis after a breast cancer diagnosis is similar for combined hormone therapy users and non-users, increased breast cancer mortality on a population basis can be expected.“
In plain English, women who develop breast cancer after taking HRT are just as susceptible to bad outcomes from their breast cancer as women who did not take estrogen and progestin and developed breast cancer spontaneously. Hormone-induced cancers are neither easier to treat nor less dangerous.
We know that millions of women believe that “natural” or “bio-identical” hormones pose no risk of cancer or cardiovascular disease. We wish we had data like the Women’s Health Initiative to support that belief. There has never been a study comparable to the WHI for natural estrogens and progesterone. Consequently, we can draw no conclusions one way or the other.
Susan Love, MD, one this country’s greatest breast cancer physicians told us candidly that she did not think there was any significant difference between natural and synthetic hormones. She pointed out that women who have naturally high levels of hormones are at greater risk for breast cancer. You can’t get any more “bio-identical” than your own hormones. Dr. Love commented that very little research has been done on such formulations, and there is no evidence that they are safer than other types of estrogen and progesterone.
One physician summarized the dilemma like this:
Q. I am a family physician. Back when we were prescribing hormone replacement therapy (HRT) regularly, I used to offer women the option of plant-based estrogens instead of synthetic hormones. Since we learned the results of the Women’s Health Initiative (WHI), though, I’ve viewed all estrogens as carrying similar risk until proven otherwise.
There are practitioners who are saying that bio-identical hormones are safer. They encourage women to use them as an alternative for menopausal symptoms. Is there any research that shows that the risks are lower for plant-based HRT than for synthetic?
A. There is no comparable study of plant-based estrogens, and there is not likely to be one. The Women’s Health Initiative was a very large, expensive study, funded by the National Institutes of Health. Women were randomly assigned to receive Prempro or placebo. The results showed that postmenopausal hormones increased the risk of breast cancer, heart attack and stroke.
Women’s health expert, Susan Love, MD, responded to a question like yours: “I think that it is very unlikely that bio-identical hormones, as they’re called, will be any safer than Prempro.”
We have summarized information on estrogen and natural treatments for hot flashes and other symptoms in our Guide to Menopause.