Comments by Dr. Hurlock about the “Latest WHI Study” published Oct 20, 2010 which reports increased breast cancer diagnosis and breast cancer mortality in Prempro users.
This is yet another somewhat misleading follow up report from the WHI. This time the authors report that women who were on Prempro (not estrogen by itself), were 25% more likely to be diagnosed with breast cancer and also were more likely to die from breast cancer.
The increased detection of breast cancer is very consistent with many other studies showing a slight increased rate of detection in HRT users. To put this in perspective, having a college degree is associated with a 36% increased risk of being diagnosed with breast cancer and being obese is associated with a 48% increase in the risk of being diagnosed with breast cancer. So a 25% increase is not too impressive.
As for the increase in breast cancer mortality, that does not match most of the preexisting data. Most of the other studies that have measured breast cancer mortality in HRT users have reported a decrease in mortality from breast cancer. So therefore, the jury is still out on that, and it would not make sense to think that this study is correct when so many other studies have found the opposite result. We simply need to see more data on this to really know what the truth is.
But the biggest problem with this report is that the authors conveniently did not report total mortality rates in the entire group, they only reported mortality rate among those who had breast cancer. I e-mailed the lead author this morning to ask why the total mortality rates were not reported, and his answer was the following: “We have not reported all cause mortality for the 11 year follow up in the E+P trial. That analysis is pending and will be included in a separate publication.” Of course that really does not answer the question of WHY those data were not included, it just says that they were not included, and the writers group has chosen to continue to sit on those data and not share them with the public for now. But the reason that that omission is important is that breast cancer mortality is not a very big contributor to total mortality for women. Only 4 out of every 100 mortalities in women are due to breast cancer. In contrast, about 44 of those mortalities are due to heart disease. So, in the worst case scenario, if Prempro does indeed slightly increase mortality from breast cancer as this study claims, but at the same time it is dramatically reducing mortality from heart disease, which is a much more common cause of mortality, then we still have a large net benefit to mortality. Most good studies that have measured the effect of HRT on mortality in women who start HRT at the onset of menopause have shown about a 40-50% reduction is heart disease mortality. If that were true also in this study (we don’t know yet because they continue to hide those data), then for example, out of 100 women, HRT might save 20 women from cardiovascular death while 3 more women may die from breast cancer. So we have a net benefit of 17 lives saved out of those 100 women.
It is known that HRT’s preventive effects are strongest if HRT is initiated at the onset of menopause, when the blood vessels are still healthy. If HRT is started after some hardening of the arteries has already occurred, then HRT cannot prevent heart disease as well.
Because the population in the WHI was so old at the onset of this study (average age 63), it is unlikely that we will see a 40% reduction in cardiovascular mortality in this group. The benefit will likely be smaller. But even at 7 years in this population the total mortality was beginning to be lower in the Prempro group compared to the placebo group as reported in their 2002 publication. So perhaps we may see a 15% reduction in total mortality (if they ever decide to publish their data!). This would still yield a net reduction in total mortality even if breast cancer mortality is doubled (which is not yet clear.) Consequently, that would have significantly watered down the SHOCK and FEAR effect on current HRT users of their current report.
This is likely the answer to my question of “Why?” the total mortality data were not included in this report. After all, as the previous leader of this study, Dr. Jacques Rossouw, stated in the Wall Street Journal July 9, 2007: “Study officials wanted to make a dramatic statement. Our main job at the time was to turn around the prevailing notion that hormones would be useful for long-term prevention of heart disease. That was our objective. That was a worthy objective which we achieved.” Their admitted anti-estrogen agenda was and still is pervasive in every report that has come out of the WHI. Hint: Perhaps “WHI” stands for “We’ll Hide Information”. Seems like it. My recommendation is to ignore them.
Will then try the patch if that doesn't work. Thanks again!