(February 25, 2008 - Insidermedicine) Combined hormone replacement therapy increases the likelihood that postmenopausal women will experience abnormal mammogram and breast biopsy findings and compromises the diagnostic ability of both modalities, according to research published in the Archives of Internal Medicine.

Here are some recommendations regarding the use of hormone replacement therapy in postmenopausal women:

•    There are many effective options to be considered for the relief of menopausal symptoms; although hormone therapy is often the most effective treatment, it is not always necessary.

•    Periodically re-evaluate women on hormone therapy to determine if it is still indicated, particularly if there have been changes in their health status.

•    Women who have recently discontinued hormone therapy are at risk for rapid bone loss; they must be identified and monitored appropriately to ensure continued bone health.

Researchers out of the Los Angeles Biomedical Research Institute at Harbor–UCLA Medical Center studied over 16,000 postmenopausal women who participated in the Women's Health Initiative (WHI) clinical trial. For this trial, the women were randomized to treatment with the combination of 0.625 mg conjugated equine estrogens plus 2.5 mg medroxyprogesterone daily or placebo.

During a mean treatment period of 5.6 years, 199 women in the hormone replacement therapy group and 150 women in the placebo group developed breast cancer. Overall, 35% of women in the treatment group had mammograms with abnormal findings, compared with only 23% in the placebo group. In addition,  breast biopsies occurred in 10% of the hormone-treated women, compared with only 6.1% of those on placebo. Despite the presence of a greater number of more advanced breast cancers in the hormone therapy group, biopsy actually diagnosed cancer less frequently in this group than in placebo-treated patients. This effect was still present to a lesser degree after discontinuation of HRT.

Today's research demonstrates how hormone replacement therapy compromises the diagnostic ability of two of the most commonly used diagnostic tools. These adverse effects on diagnostic tests for breast cancer should be discussed with women considering hormone replacement

For Insidermedicine in Depth, I'm Dr. Susan Sharma.