WHI said there was an increase in breast cancer. What is the truth about that?
The breast cancer information from WHI was startling. As it turns out, in the Prempro arm, the women who were using the combination oral product Prempro, there was no statistically significant increased risk of breast cancer! That means that any slight increase in the incidence of breast cancer in the women who took Prempro could have been from chance rather than from the Prempro! Even more fascinating about the WHI study, was that in the Premarin-only arm of the study, which included only women who had had prior hysterectomy, there was a statistically significant DECREASED risk of breast cancer, regardless of age, in the women who actually took their medication greater than 80% of the time!!! Over the years, the data on hormone therapy and its impact on breast cancer have shown no consensus. There are papers that show a slight increased risk, those that show no change in risk at all, and those that show a slight decreased risk. This means that the worst case scenario is that there may
