Hormone replacement therapy on mammographic density among postmenopausal women

Objective To investigate effects of hormone replacement therapy with conjugated equine estrogen (CEE) in different doses combined with medroxyprogesterone acetate ( MPA) on mammographic density among postmenopausal women and its clinical significance. Methods Ninety eligible postmenopausal women were randomized into three groups with varied treatment continuously for one year, Croup A receiving 0.3 mg CEE with 2 mg MPA and caltrate 600 mg and vitamin D 125 U daily; Group B receiving 0. 625 mg CEE combined with 2 mg MPA and caltrate 600 mg with vitamin D 125 U daily; and Group C receiving caltrate 600 mg and vitamin D 125 U daily. Mammographic density was analyzed using Wolfe and semi-quantitative methods for all of them and compared each other one year after treatment, as well as mammographic density before and after treatment in Groups A and B. Results One year after treatment, mammogrphic density reached the highest in postmenopausal woman of Group B and the lowest in those of Group C, with significant difference among the three groups (P ＜ 0. 01) and between Groups A and C (P ＜ 0. 01) and between Groups B and C ( P ＜ 0. 05 ). Mammogrphic density with semi-quantitative method increased significantly in Group A ( P ＜ 0. 05 ) and Group B ( P ＜ 0. 01 ), respectively, after treatment as compared with that before it. Change in mammografic density before and after treatment was greater in Group B than that in Group A, but not reaching statistically significant level (P ＞ 0. 05). Conclusions Hormone replacement therapy can cause the increase of mammographic density in postmenopausal women, possibly in a dose-dependent pattern, which suggest that HRT has side effect on breast tissue and the lowest effective dose of estrogen should be selected in HRT. Mammographic density can be used as an indicator to monitor side effect of HRT on breast. Key words: Estrogen replacement therapy;  Mammography;  Menopause