Can Hormone Replacement Therapy Compromise a Mammogram's Accuracy?
However, Rutter, a researcher with Group Health Cooperative's Center for Health Studies in Seattle, also found that women who stopped taking HRT during the study had decreases in breast tissue thickness, suggesting that the effect of HRT may be temporary and reversible.
A similar study presented last month at a radiology meeting by researchers from Germany found that HRT also compromises the accuracy of breast MRI scans, which are occasionally used after a woman has had a suspicious finding on a standard mammogram. The German researchers say the problem is so significant they believe women should actually consider stopping their hormone therapy a few weeks prior to having an MRI to reduce the risk of either missing a cancer that is hidden by increased breast tissue or detecting something that looks like a tumor but is only an increased mass of normal breast tissue.
But Zaslow says while the suggestion to stop HRT before having a breast scan may be reasonable in some cases under doctor supervision, it still needs to be studied further. For now, the women taking HRT should not stop therapy without talking first with their doctor to determine if the benefits of the therapy outweigh any potential risk.
"Women need to talk to their doctors about why they're taking HRT. If they're taking it for severe hot flashes and it's helping them, that may be more important than a slight possible decrease in their mammogram sensitivity," she says.
Stephen Taplin, MD, a co-author of the new study, agrees, saying in a press release that since there may be serious health risks associated with starting and stopping HRT, "it's too early to suggest that women stop taking the drug prior to their mammograms."