MAMMOGRAPHIC CHANGES IN POSTMENOPAUSAL WOMEN ON HORMONAL REPLACEMENT THERAPY

The purpose of this study was to investigate the extent of the effects of hormonal replacement therapy (HRT) on the mammographic breast patt ern in postmenopausal women. In a hospital-based study mammographic ex aminations of 81 postmenopausal women were evaluated retrospectively, before and after 1-2 years of treatment with oestrogens or a combinati on of oestrogens and progestagens. Each individual mammographic film w as examined separately and the glandular tissue was classified accordi ng to a modified Wolfe classification. In a screening-centre-based stu dy two consecutive mammograms, with a 2-year interval, of 645 women, o f whom 70 were using some kind of hormone therapy, were evaluated retr ospectively. In the hospital-based study 31% of patients treated with combination HRT showed an increase in fibroglandular tissue compared w ith only 8.7% in the group treated with oestrogens alone. The differen ce was statistically significant (p = 0.046). In the screening-based s tudy 14.3% of the women using hormonal therapy showed an increase, whe reas in the non-users no increase was found (p = 1.24 x 10(-10)). Afte r beginning HRT many women (between 14 and 25% in our experience) can be expected to undergo a mammographically detectable increase in fibro glandular tissue. Radiologists should be aware of the aetiology of suc h changes, and can obtain information on HRT most conveniently by havi ng the technologist routinely question each patient.