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 Interview with Dr. Isaac Schiff, Joe Vincent Meigs Professor of Gynecology at Harvard Medical School and Chief of the Vincent Obstetrics and Gynecology Service at the Massachusetts General Hospital.
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CBS CARES: Do you think that some women and even some doctors may have overreacted to the results of the WHI study, or are the risks such that women should try to avoid these hormones if possible?
DR. SCHIFF: If a woman has no contraindications and she's having bad hot flashes, and/or sexual symptoms, she should try to relieve those symptoms to improve her quality of life. Hormones can relieve these symptoms. But women see a newspaper with a screaming headline, "Women who take hormones have a 33 percent increased risk for breast cancer," and they decide to stay away from hormones, and continue to suffer.
The average listener, viewer or reader will assume that if they take hormones, they have a 33 percent chance of getting breast cancer. That's not the case. The reality is that, if you took 1,200 women aged 55 to 59, not on hormones, in the next 12 months, three out of 1,200 will get breast cancer. If they were on hormones for more than five years, four out of 1,200 will get breast cancer.
When you go from three women in 1,200 getting breast cancer to four in 1,200, that's a 33 percent increase. So, the increased risk is there and needs to be disclosed to women. But the degree of risk is more easily understood when stated as the number of women likely to get breast cancer rather than as a high percentage that can easily be misinterpreted.
CBS CARES: Prempro seems like an important drug, but it was developed 10 years ago and Premarin 50 years before that. Have there been more recent breakthroughs in the development of new hormonal drugs?
DR. SCHIFF: There has been. In my view, one of the major breakthroughs over the past twenty years has been the estrogen transdermal approach. I think the estrogen skin patch delivers estrogen in really the most physiologically similar form to how they would naturally be in the woman's body. It's important to mention because it could be helpful for women if they have some kind of liver problem, or maybe a history of phlebitis, but again you still have to be careful in this situation. And the main point is for the woman who theoretically believes she would like to have exactly what her ovaries made and to get it into her body that way, the patch or a cream is the simplest way to do so.
CBS CARES: The transdermal patch seems like an important new method of delivering a prior drug. But, are there any chemically new hormonal drugs that have been approved or look promising?
DR. SCHIFF: Yes, there is a drug called Tibolone, which is not available yet in the United States, but is used in Europe, and is thought to have estrogen components and testosterone components and progesterone components all at once. It is said to help with hot flashes, to help with sex drive, to help with moods-really, to help with everything. But it is still not approved in the United States because it lowers HDL, which is the good cholesterol, and we worry ultimately about heart disease. The other concern about Tibolone is, in the Million Women's Study in the UK, it actually showed an increase in the risk of breast cancer.
CBS CARES: What's the difference between "bio-identical hormone therapy" and conventional hormone or estrogen therapy?
DR. SCHIFF: Bio-identical or natural hormone therapy is used to describe hormone treatment with individually compounded recipes of certain steroids in various doses. And, they are the ones occurring naturally in women and thus do not refer to phytoestrogens.
The word "natural" implies that the substance is somehow safe and more effective than synthetic hormones, but what exactly is a natural hormone? When administered orally, some of these natural hormones are altered in the gut. If one wants the ideal hormone and to use what the body used to make, then one would consider using estradiol and avoid the gut by using it in either a patch or a cream.
CBS CARES: What is the difference between FDA-approved bio-identical estradiol and prometrium (bio-identical progesterone), and the bio-identical estradiol and progesterone, respectively, that are developed by compounding pharmacies?
DR. SCHIFF: Well, estradiol is estradiol, whether it's made by a compounding pharmacy or a pharmaceutical company. However, because bio-identical hormone prescriptions filled by compounding pharmacies are customized to individual patients' needs, there's not a consistency to the dosing. While there are the Professional State Boards of Pharmacy and an International Academy of Compounding Pharmacists, the FDA is not involved in approving hormones synthesized by compounding pharmacies.
By contrast, the FDA has a much tighter control over the hormones in drugs that it approves. When you're getting a dose of an FDA-approved drug, you know it's got that exact amount. With hormones made by a compounding pharmacy, on the other hand, there may not be the same stringent controls as are applied to drugs, and you don't know exactly what a compounding pharmacy is doing. There have been studies that look at concentrations of hormones from different compounding pharmacies, with very different
results.
CBS CARES: Are bio-identical hormones as effective as conventional hormones, and are they as safe or safer?
DR. SCHIFF: There is some anecdotal evidence suggesting efficacy, and there are women on bio-identicals who say that their symptoms have improved. But there's no scientific evidence that they're as safe, safer or as effective. They just haven't been scientifically tested. Most of our current evidence-based knowledge of hormone therapy have been obtained with Premarin because it has been around the longest, or estradiol valerate, a different form of estrogen used in Europe and not available in the United States.
While it does make sense that something bio-identical could be safer, a lack of controlled clinical trials, and the label "natural" cannot and must not be interpreted as evidence of its safety. So, it appears that there is no proven advantage over conventional hormone therapy.
CBS CARES: Are there any advantages to taking a synthetic hormone versus a "natural" one?
DR. SCHIFF: The most common synthetic estrogen is ethinyl estradiol, which is predominantly in the birth control pill. Remember, estradiol, the natural hormone the ovary makes, gets converted to estrone when taken by mouth. Not only that, but it leaves the system very quickly. For a birth control pill, you want something that is going to last at least 24 hours until one takes the next pill, or else it's not going to function very well as a contraceptive. And so if you add an ethinyl group, which is a kind of chemical, onto the estradiol, it prevents the liver from breaking it down rapidly. And it persists in the body for some period of time.
The physician would usually prescribe conventional hormone therapy because we know more about conventional hormone therapy. It's measured. As we've discussed, we have no data to say bio-identical therapy is safer or effective. So why not use the thing that we have the most information about?
CBS CARES: Is prescribing bio-identical hormones a reasonable thing for some doctors to do?
DR. SCHIFF: Oh, sure. Prescribing bio-identical hormone therapy is not bad medicine. These doctors are thinking theoretically that they're using the most natural form of hormones and that they may present a lower risk than conventional hormones. They measure hormone levels in the blood to see what's too low or too high, and then prescribe doses that correlate to the "correct" hormone levels. The main reason for taking hormones is symptom relief, so you want to make sure your individual "correct" levels provide enough hormones to feel better. There is no "correct" blood level. The lowest dose that relieves symptoms is appropriate.
CBS CARES: What would you say to a woman who believes bio-identical hormones have lower risks than conventional hormones?
DR. SCHIFF: I'd say to her that women who go through a later menopause and/or start having periods at an earlier age, and are therefore exposed to estrogen longer, have an increased risk for breast cancer. This is true even though the estrogen they're exposed to is the natural form, made by their own bodies. In fact, for every year that a woman continues to have periods, her risk for breast cancer continues to go up just as much as if she takes hormone therapy.
The point about bio-identicals is that theoretically, they are what the body made, but just because the body made it doesn't mean it's safe. So the idea that bio-identicals are better or safer is mostly theoretical since there are no scientific studies to prove safety or effectiveness. I think it's a fallacy to assume that a particular hormone is safer or riskier than the others. And the Million Women study showed that whatever hormone you were using, the risk for breast cancer went up.
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