Impact of Oral Levonorgestrel for 1 Year on Mammographic Density in Menopausal Hormone Therapy / 대한폐경학회지

ABSTRACT

OBJECTIVES: We evaluated changes in mammographic density (MMGD) after hormone therapy (HT) using levonorgestrel (LNG) in Korean postmenopausal women. METHODS: In this retrospective study, 58 healthy postmenopausal women with no history of prior HT were included. Twenty-three women were given a cyclic regimen of estradiol valerate (E) 2 mg/day + LNG 0.075 mg/day and 25 untreated women served as a negative control and 10 women treated with continuous combined regimen of conjugated equine estrogen (CEE) 0.625 mg/day + medroxyprogesterone acetate (MPA) 2.5 mg/day as a positive control. Mammography was obtained at baseline and 1 year later, and MMGD was assessed. In addition, the change in the proportion of the dense area after HT was assessed using the J-image program. Data were analyzed with analysis of variance and chi-square or Fisher's exact test. RESULTS: There were no significant differences in baseline characteristics among three groups. After 1 year of HT, increase of BI-RADS grade in CEE + MPA group (7/9, 77.8%) was higher than in E + LNG group (2/16, 12.5%; P = 0.001). But there was no difference between untreated group (1/19, 5.3%) and E + LNG group (2/16, 12.5%; P = 0.446). In subgroup analysis of women with BI-RADS grade 3 at baseline, no significant difference. Changes in the proportion of dense areas assessed by the J-image program showed similar results. Regression analysis revealed that there was no correlation between baseline dense area and changes after HT in E + LNG group. CONCLUSION: HT using LNG did not influence MMGD in Korean postmenopausal women. Further study on breast cancer risk may be needed.