"Breast Cancer Seen as Riskier with Hormone," trumpets the oddly worded headline in this morning's New York Times, which summarizes the JAMA findings also released today.
No, this isn't old news, though it's based on the Women's Health Initiative study that was stopped several years ago because the estrogen-using participants kept coming down with dread diseases. Long-term results have recently been analyzed, and women who take Prempro are clearly at greater risk than women who do not.
But the headlines are misleading for several reasons.
First, the WHI studied only one form of estrogen--and it's the one most likely to cause problems. The WHI studied women using conjugated equine estrogens. These are laboratory produced hormones that are not biologically identical to the hormones produced in a woman's body. Premarin is based on the estrogens found in PREgnant MAres' uRINe, some of which are much more potent than human estrogens. It is somehow unsurprising to learn that long-term use of substances that do not naturally occur in the human body may have deleterious side effects.
Second, estrogen is probably not the culprit in increased breast-cancer risks anyway (though it may increase other risks). According to the National Institutes of Health, the risk does not apply to hysterectomized women who take only estrogen, not estrogen plus some form of progesterone. Since about 1/3 of all American women will have had a hysterectomy by age 60, that's a fair number of women who can apparently take estrogen without raising their risk of breast cancer - and who may need to do so, since they have lost their natural source of the hormone.
Third, biologically appropriate hormones are under-researched. Bioidentical hormones, though synthesized from plant sources, are "identical in molecular structure to the hormones women make in their bodies" (see this explanation and list of bioidentical hormone medications). Reputable studies of bioidentical hormones, however, are hard to find, and to my knowledge no longitudinal study comparable to the WHI study of Premarin and Prempro has ever been made. Are these hormones safer than hormones that do not match those our bodies naturally produce? A lot of women think so, but we don't know yet.
So what is a woman to do?
Well, if we don't need hormone replacement therapy, we certainly shouldn't use it. If we need it for hot flashes only, we should quit using it periodically to see if the need has passed. But if for some reason we need to use HRT for many years, we don't need to panic. Every medicine has potential side effects, and some risks are worth running.
To minimize the risks, we can look for hormone formulations that mimic human hormones. We can look for delivery methods, such as the patch, that appear to be safer than HRT in pill form. We can monitor those body parts that our HRT use may be slightly endangering.
And just maybe we need to consider our mortality. I'm not going to live forever. I can't avoid every possible risk. Even if I were able to give up absolutely everything that's bad for me, would I really be better off? Would I live longer, or would it just seem longer? Would I be healthier, or would I worry myself to death?
"If it feels good, do it," we boomers liked to say when we were young and immortal. Well, maybe that's not an entirely helpful philosophy. And yet feeling bad so as to avoid a very small risk may not be such a great philosophy either.
Several years ago I was explaining to a middle-aged doctor why I hoped she would prescribe an estradiol patch for me. "I have to tell you about all the potential problems," she told me. "But if anyone wants to take away my estrogen, they'll have to pry it out of my cold, dead hands."