can't edit the comment I made previously but wanted to add the actual percentages to further clarify the increased risk of breast cancer when on hormones.
From the New York Times ~ a woman’s risk of having breast cancer between the ages of 50 and 60 (the average age of the women in the WHI study) is around 2.3 percent. The Women's Health Initiative Study noted an increase in that risk of 26 percent and that's the number that was widely reported. That percentage is huge and scary. In actuality the 26% increase increased the risk from a 2.3 percent chance to a 2.94 percent chance, really a very very small increased risk. And again, this was on oral estrogen and synthetic progestin.