Combined Hormone Replacement Therapy and Breast Cancer Risk

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Combined HRT and Breast Cancer

The link between hormone replacement therapy and breast cancer has been the subject of extensive medical research in recent years. Combined hormone replacement therapy (HRT) was used on women to relieve them of menopausal symptoms. However, a large study conducted by Women’s Health Initiative (WHI) in 2002 indicated a possible connection between HRT and different types of cancers in women, including breast cancer. Subsequent detailed studies have indicated that a regular use of HRT increases the risk of breast cancer by about five to six percent every year in comparison to the risk for a woman who is not undergoing this therapy.

The breast cancer risk also appears to increase with prolonged usage of the therapy. Another indication from the studies is that women taking this therapy are more likely to be detected with breast cancer at an advanced stage. But the risks with HRT only pertain to current and recent users. The risk of breast cancer begins reducing once the woman stops HRT, and within three years the risk is equivalent to that of general population. However, many concerns still remain to be addressed about the relationship between HRT and breast cancer, and the research is still ongoing in this area.

Estrogen and the Risk of Breast Cancer

Several studies have also evaluated the relationship between estrogen replacement therapy (ERT) and breast cancer. The study by WHI indicated that ERT did not result in any change in the risk levels of the user against breast cancer. However, an extensive study conducted in the UK has reported a very marginal increase in the risk of breast cancer for women who underwent ERT. The risk may range anywhere between one and three percent per year with this therapy.

In any case, most studies have indicated that progestin has a stronger role to play in increasing breast cancer risk than estrogen. Combined hormone replacement therapy and breast cancer have a clearer association because the combined therapy involves replacement of estrogen plus progestin. That makes it important that any woman undergoing the combined therapy should be annually examined for any signs of breast cancer. The U.S. FDA recommends that women should consult with their doctors and do a risk-benefit analysis particularly before going ahead with a combined therapy of progestin and estrogen.

Options of Natural Supplements and Herbal Alternatives

The use of combined HRT to reduce menopausal symptoms has reduced substantially in recent years due to its possible linkages with various types of cancer. However, this has also led to the introduction of a number of over-the-counter herbal medications and natural therapies to address the symptoms of menopause. Among the common natural products that are available in the market today are various soy-based products, vitamin supplements, and herbal products such as red clover and black cohosh.

Herbal supplements are usually not treated as drugs but as dietary supplements. The U.S. FDA has not conducted any evaluation regarding the safety or usefulness of these OTC natural products. There is a need to conduct proper scientific research to determine the benefits and safety issues with these alternative solutions to HRT.


American Cancer Society:

National Cancer Institute: