The study — which was presented to the World Congress on Menopause, held in Cancun, Mexico — may be the first step in identifying which types of HRT have minimal effect on breast cancer. It also opens the door to the long-term possibility of personalizing HRT according to a woman’s specific genes.
The report resulted from a study conducted by Sweden’s famous Karolinska Institutet, which recruited a group of 30 healthy women. Researchers used a needle biopsy to take two samples of breast tissue from each woman.
Each tissue sample was then tested in a laboratory to identify the 16 genes known to be associated with an increased risk of breast cancer. The women were then split into two groups. Each group was given one of two different types of HRT for two 28-day cycles.
One group was given estrogen that was applied to the skin in a gel. The other group received progesterone that was taken orally.
The researchers used PCR analysis to determine that the hormone therapy changed the expression of 8 out of the 16 genes in the women taking the estrogen, but only four out of the 16 genes in the women who took the progesterone.
It shows that varying the HRT and the way it is taken can have very significant effects on the genes associated with breast cancer.
The results give medical experts more information about the best ways to limit or even eliminate the risk of developing breast cancer for women using hormone replacement therapy. It has been heralded as a breakthrough in the area of HRT research and may serve as a stepping stone to the next level of research that could make HRT even safer than it already is.