Evaluation of Mammographic Density Changes during Estrogen and Estrogen-Progesterone Therapy in Postmenopausal Women

Background/Objectives: To determine the effects of estrogen and estrogen plus progesterone on mammographic density in postmenopausal women. Patients and Methods: In a descriptive cohort study, ba seline and 12-month mammograms were obtained from 97 healthy postmenopausal women, aged 45-55 years. Estrogen or combined estrogen and progesterone replacement ther apies were used for them. After one year, we classified breast density in the first and second mammograms according to Breast Imaging Reporting and Data System (BIRADS) as patterns 1 (mostly fatty) through 4 (mostly dense tissue). Results: None of our cases had a decrease in density, while 35.1% showed an increased density. The results showed that an increase in mammographic density had no significant association with the type of prescribed hormone (P=0.77). In cases with no change in density, the parity was 3.51.86; while in the group with one-level rise, it was 4.241.84; and 5.21. 92 in the two-level rise group. Statistical analysis showed that changes in density had significant association with parity in our cases (P=0.015). Conclusion: HRT was associated with increases in mammographic density, suggesting that increasing mammographic density may be a marker of elevated breast cancer risk in postmenopausal women who use postmenopausal hormone replacement therapies. However, the link between changes in breast density resulting from hormone use and the change in breast cancer risk remains uncertain.