Probably the major cause for concern regarding post menopausal HRT (hormone replacement therapy) highlighted by the WHI study was an increased risk for breast cancer. This finding applied to women in the WHI who were using combination estrogen and progesterone replacement. Progesterone is given to counteract the effect of estrogen to cause uterine (endometrial) cancer but is not crucial for relief of post-menopausal symptoms. Interestingly, women who used estrogen replacement alone (without the progesterone) actually showed no increase and possibly even a reduction in invasive breast cancer after 7 years on treatment. In the group of women who started “estrogen only” replacement more than 5 years after entering menopause, the reduction in breast cancer was even more pronounced. Experts therefore conclude that “estrogen only” HRT is likely to be considerably safer from a breast cancer point of view, and starting estrogen 5 years after menopause reduces the cancer risk even further.
The relationship between estrogen use and breast cancer risk is further complicated by the finding that post-menopausal women using HRT who develop breast cancer appear to have better survival and less aggressive tumors than post-menopausal women who are diagnosed with breast cancer who never used HRT. Breast cancer may not be caused by estrogen, but cancer may grow more rapidly in the presence of estrogen. This doesn’t sound like an advantage but small undetected cancers may grow rapidly with HRT so that they can be seen on mammography and removed before they can spread.
New drug combinations in development offer hope to women who are looking for HRT alternatives. A class of drugs known as SERMS of which Evista is a member, used in combination with estrogen has shown promising results in clinical studies. A SERM will protect against the uterine cancer causing effect of estrogen so progesterone is no longer needed with HRT. This immediately reduces many of the undesirable effects of HRT found in the WHI including breast cancer risk and producing better cholesterol effects. This combination of drugs is referred to as a tissue-selective estrogen complex (TSEC). Other advantages of TSEC treatment are improvement in bone density (lower osteoporosis risk) and possible reduction in coronary artery disease development. Although TSEC treatment is not yet FDA approved for treatment of post-menopausal symptoms, individual doctors can prescribe this if they feel the available information is favorable and the risk/benefit ratio is in favor of the patient’s well being.
Finally, there is the issue of blood clots associated with estrogen treatment. This is likely due to the effect of estrogen to alter the balance of certain blood proteins that favor blood clot development. My thought is that adding a simple baby aspirin daily may reverse or significantly reduce risks associated with increased blood clotting with estrogen, just as baby aspirin is now recommended for those at increased risk of heart attack. Aspirin is unlikely to be helpful to prevent blood clots in veins referred to as DVT but this is not completely certain. As with all medications there are downsides to aspirin such as gastric irritation and ulcer bleeding but these risks can be assessed by the individual and their doctor.
(This information is for educational purposes only and does not constitute medical advise or establish a doctor patient relationship)
Gary Pepper, M.D.
Editor-in-Chief, metabolism.com