Like any medical treatment, there are some risks associated with HRT, the most concerning
of which for women is breast cancer. This is a hotly debated topic in the medical literature
as well as in the media. Unfortunately, it a topic that is often misrepresented, misinterpreted,
and taken out of context, leading to much confusion among women seeking relief from
menopause and restoration of hormonal balance for longevity.
One of the most famous HRT trials was started in the late 1990’s and ended a few years later.
This collection of studies is referred to as the Women’s Health Initiative (WHI). This is the study that publicized the breast cancer risks of HRT. Follow-up publications from the decade-old data of that trial continue to emerge to this day. The WHI was a study using oral pill forms of non-human, non-identical hormones known as Conjugated Equine Esters (CEE) and Progestins. There were several arms to the study, the one where both CEE and Progestin was used and the one where only CEE was used.
In Summary, Those Studies Found:
- Women using only conjugated non-identical estrogen (CEE) had a lower risk of breast cancer (This was confirmed in long-term follow-up studies)
- Women using conjugated non-identical estrogen and non-identical progestins had a higher risk of breast cancer (The WHI was stopped due to the increased risk of breast cancer from this combination therapy)
- All HRT reduced risk of osteoporosis and colon cancer
Around the same time as the WHI, a large French study (EPIC-E3N) enrolled nearly 100,000 women and showed that:
- Women using bio-identical estradiol given through the skin had no increase of breast cancer
- The use of progestins appears to have the greatest breast cancer risk
- A follow-up study of this population showed a modest increase in breast cancer from combined oral estrogen/progesterone HRT (The risk was the lowest for bio-identical hormones such as estradiol and progesterone. The risk was highest for women using any estrogen with progestins)