ABSTRACT
PURPOSE: To determine the frequency and distribution of parenchymal changes on mammography before and after hormone replacement therapy. MATERIALS AND METHODS: Mammograms of 100 postmenopausal women who underwent hormone replacement therapy without breast disease were evaluated. Mammograms obtained annually after hormone replacement were analysed and compared with that of pretreatment. In addition, mammograms of control group and treatment group were compared. RESULTS: An increase in density of breast parenchyma was seen on the mammogram of 20 women(20%) receiving therapy. The mammograms from the control group showed no change. Mammographic changes were detected at first year in 13 women, 2nd year in 4 women, 3rd year in 2 women, and 4th year in 1 woman (average,19 months). CONCLUSION: We conclude that increase in mammographic density following postmenopausal hormone replacement therapy is not uncommon(20%).