I must admit that I was a bit skeptical of the conclusions drawn by the media about the latest analysis of the Women’s Health Initiative (WHI) data. The WHI study has generated many different spin-off articles about hormone replacement therapy and its potential link to breast cancer. This latest review suggests that the increased risk for cancer persists up to five years after stopping HRT treatment for menopausal symptoms. I asked Revolution Health expert and past president of the American College of Obstetricians and Gynecologists, Dr. Vivian Dickerson, to help us put this new article into context.
Dr. Val: What does this new study contribute to our understanding of the risks of HRT?
Dr. Dickerson: First of all the women in this study were not on estrogen alone (the usual treatment for women who have had hysterectomies). Their HRT consisted of a combination of Premarin (estrogen) and Provera (progesterone). The original study indicated a slightly higher (barely statistically significant) increased risk for cardiovascular disease (CVD) and a statistically significant increased risk in breast cancer (but relative risks were less than 1.5 for both, which is very small).
Now all this new analysis tells me is that the CVD risk appears to extinguish or become negligible after three years though there is still an increase in breast cancers (compared to placebo) but the difference was not statistically significant. This is interesting in that it does add some plausibility to the claim that the reason breast cancer rates declined so significantly in the year(s) after WHI is because of all the women who quit taking HRT. It doesn’t prove anything, but just more grist for the mill. (Unfortunately I don’t see sub-group analyses of the women who chose to continue HRT after the end of WHI and those who quit from the treatment group.)
The study authors used some fancy math to demonstrate that there was a statistically significant increase in all-cause mortality (including breast cancer) for the women in the HRT group. Since the relative risk is so low, all they can say is that there is no reason to use HRT as a protective or primary preventive measure against heart disease, which we’ve known for many years now.
Dr. Val: Would you change your HRT recommendations based on this new analysis of the WHI data?
Dr. Dickerson: I wouldn’t change a thing that I am doing or counseling. These data are weak and the differences are not robust in any parameter.
So there you have it, ladies. No need for heightened alarm based on this analysis of the WHI data, especially if you have never been on the Premarin/Provera cocktail. It would be really helpful to compare breast cancer rates in women who stopped HRT versus those who continued it after the initial WHI data were released. Let’s keep our fingers crossed that this subgroup analysis is next up for publication.
Addendum: My friend and HRT expert, Dr. Avrum Bluming, kindly wrote me an email to further underscore the dubious nature of this study’s findings. Here’s what he said:
“The paper reads more like a lawyer’s presentation then a scientific article (i.e. it makes points followed by the disclaimer that the findings represented are not statistically significant—but the points have been registered). Instead of concluding that the very small increased risk of harm associated with estrogen and progesterone combination therapy (reported in the original studies, which were of questionable significance in the first place) are not found 2+ years after HRT was stopped, they find new risks (lung cancer) to allow them to conclude that administration of HRT results in delayed increased risks.”This post originally appeared on Dr. Val’s blog at RevolutionHealth.com.