Impact of Medroxyprogesterone Acetate by Type of Combined Oral Estrogen on Mammographic Density in Korean Postmenopausal Women

Abstract

Objectives: We determined if the impact ofmedroxyprogesterone acetate (MPA) co-administered with conjugated equine estrogen (CEE) or estropipate differed on mammographic density (MMGD) in Korean postmenopausal women. Methods: In this retrospective study, 53 healthy postmenopausal women without prior hormone therapy (HT) use were included. Smokers, habitual drinkers, womenwith a bodymass index ≥ 27 kg/m2, andwomenwith a history ofmammoplasty or breast cancer were excluded. HT usingMPA(n = 26) consisted of the following two groups: CEE (n = 10) and estropipate (n = 16). Twenty-seven untreated women served as the control group. Mammography was obtained at baseline and 1 year later, and MMGD was assessed based on the breast imaging reporting and data system(BI-RADS) by one radiologist who was blinded to treatment. 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 clinical characteristics andMMGD among the three groups. After 1 year of HT, CEE (7/10 [70%];P ＜ 0.001) and estropipate (3/16 [18.8%];P = 0.002) regimens significantly elevated the BI-RADS grade comparedwith controls (0%), and CEE induced a greater increase inMMGDthan estropipate (P = 0.033). In addition, the proportion of dense areas assessed using the J-image program increased more with the CEE regimen (7.67%) than the estropipate regimen (1.48%), but there was no statistically significant difference. Conclusion: Estropipate ＋ MPA had a less stimulating effect on MMGD than CEE ＋ MPA in Korean postmenopausal women. The change inMMGDinducedwithMPAmight depend on the oral estrogen preparation. Afurther study on breast cancer risk based on combination HT is warranted.

연구목적: 한국 폐경 여성에서 경구 에스트로겐 종류에 따른 medroxyprogesterone acetate (MPA)의 유방 치밀도에 대한 영향을 조사하였다. 연구재료 및 방법: Conjugated equine estrogen (CEE) ＋ MPA 치료 (n = 10) 및 estropipate ＋ MPA 치료 (n = 16)를 1년간 시행하여, 치료 전후의 X-선 유방촬영술상 유방 치밀도의 변화를 breast imaging reporting and data system (BI-RADS) 판독 및 J-image 프로그램을 이용하여 비치료 대조군 (n = 27)과 함께 비교하였다. 결 과: 각 군간 기초 임상 특성의 차이는 없었다. 1년의 호르몬 치료 후, 대조군 (0%)에 비해 CEE ＋ MPA (7/10, 70%; P ＜ 0.001) 및 estropipate ＋ MPA (3/16, 18.8%; P = 0.002) 치료군에서 유의한 유방 치밀도 증가가 관찰되었으며, CEE를 병합한 경우가 estropipate 병합군에 비해 높은 유방 치밀도 증가를 보였다 (P = 0.033). NIH J image로 계산한 치밀 면적의 비율 변화는 대조군에서 0.66%, CEE ＋ MPA 군에서 7.67%, estropipate ＋ MPA군에서 1.48%로 차이를 보이는 경향이 있었다. 결 론: 한국 여성에서 estropipate ＋ MPA 치료는 CEE ＋ MPA에 비해 유방 치밀도에 대한 자극 효과가 적으며, 유방 치밀도의 변화는 경구 에스트로겐의 성분에 따라 다를 수 있다. 향후 유방암 위험에 대한 추가 연구가 시행되어야 한다.