In a consensus statement, seven major professional societies have endorsed hormone replacement therapy (HRT) as the best treatment for menopause symptoms, with certain caveats. They note that this treatment is safest for women younger than 60 or within 10 years after menopause in terms of risk-benefit balance, adding that the risk of breast cancer attributable to HRT is small and the risk decreases after treatment is stopped.
This sentiment is echoed by researchers from the University of Cape Town in South Africa, who say that the evidence used to support the theory that HRT causes breast cancer is flawed. First, they point to the fact that while HRT use dropped following the publication of the Women s Health Initiative in 2002 advocating against the use of HRT rates of breast cancer also declined, and many attributed a cause-and-effect relationship to this pattern. The current authors point out that the decline in breast cancer was observed in 1999 three years prior to the publication of the WHI data. Furthermore, these studies (seeming to link HRT and breast cancer) were ecological and therefore cannot be used to prove causation, especially because the complexity of the possible interactions made eliminating the effects of confounders impossible. There is also the issue of detection bias the rate of breast cancer may have been influenced by mammographic screening methods. And there was no dose-response observed with the decline of HRT. That is, areas with high HRT use had similar rates of breast cancer compared to areas with lower HRT use.
The South African researchers therefore concluded that the ecological evidence is too limited either to support or refute the hypothesis that HRT causes breast cancer. And Dr. Nick Panay of Queen Charlotte s and Chelsea Hospital in London added that the point of the argument should now be how best to aid women facing menopause with its often debilitating symptoms that might be helped by HRT. If there is a risk, the risk is small, and the benefits of HRT can be life altering.
The analysis by the South African researchers also lends support to a review published in Cancer Journal, which highlights the fact that physicians and the public must be cautious about accepting findings by press release in determining whether to prescribe or take HRT. Researchers point out that reports disseminated to the public claimed that HRT increased risks of breast cancer development, cardiac events, Alzheimer disease and stroke. However, these reports were distorted, oversimplified, or wrong, and only served to create unnecessary alarm. This article was written at the suggestion of ACSH and has been supported with expert peer review and commentary.