Increases in serum estrone sulfate level are associated with increased mammographic density during menopausal hormone therapy.
BACKGROUND
Menopausal hormone therapy increases mammographic density. We determined whether increases in serum estrone sulfate (E(1)S) levels during menopausal hormone therapy predict increased mammographic density.


METHODS
We measured percent mammographic density and serum E(1)S levels in 428 participants of the Postmenopausal Estrogen/Progestin Interventions study who were randomly assigned to daily conjugated equine estrogen (CEE) 0.625 mg alone, CEE + daily medroxyprogesterone acetate (MPA) 2.5 mg, CEE + cyclical MPA (10 mg days 1-12 per 28-day cycle), or CEE + cyclical micronized progesterone (10 mg days 1-12). Serum E(1)S levels were determined by RIA. Information about covariates was determined by annual questionnaire. Using linear regression, we determined the association between change in E(1)S level from baseline to 12 months and change in percent mammographic density (by semiquantitative interactive threshold method).


RESULTS
After controlling for baseline mammographic density, age, body mass index, alcohol intake, parity, smoking, ethnicity, physical activity, and age at first pregnancy, mammographic density increased by 1.3% for every 1 ng/mL increase in E(1)S level (P < 0.0001). The association between change in E(1)S level and change in mammographic density differed by treatment group (greater effect in CEE + cyclical MPA group versus CEE group; P = 0.05). After controlling for treatment group, change in the ratio of E(1)S to E(1) was also positively associated with change in mammographic density.


CONCLUSIONS
Increases in serum E(1)S levels during menopausal hormone therapy are associated with increases in mammographic density. The relative contribution of E(1)S and E(1) to stimulation of breast tissue awaits further elucidation.
Crandall
Carolyn J
CJ
David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90024, USA. ccrandall@mednet.ucla.edu
Guan
Min
M
Laughlin
Gail A
GA
Ursin
Giske A
GA
Stanczyk
Frank Z
FZ
Ingles
Sue A
SA
Barrett-Connor
Elizabeth
E
Greendale
Gail A
GA
D014408:Biomarkers, Tumor / Q000097:blood; D001943:Breast Neoplasms / Q000097:blood / Q000000981:diagnostic imaging / Q000453:epidemiology*; D003280:Contraceptives, Oral, Synthetic / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D004967:Estrogens / Q000627:therapeutic use; D004966:Estrogens, Conjugated (USP) / Q000627:therapeutic use; D004970:Estrone / Q000031:analogs & derivatives* / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D020249:Hormone Replacement Therapy / Q000379:methods*; D006801:Humans; D015994:Incidence; D008327:Mammography / Q000379:methods*; D008525:Medroxyprogesterone / Q000627:therapeutic use; D008593:Menopause / Q000097:blood*; D008875:Middle Aged; D011374:Progesterone / Q000627:therapeutic use; D011372:Progestins / Q000627:therapeutic use; D011863:Radioimmunoassay; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology
D014408:Biomarkers, Tumor; D003280:Contraceptives, Oral, Synthetic; D004967:Estrogens; D004966:Estrogens, Conjugated (USP); D011372:Progestins; D004970:Estrone; D011374:Progesterone; D008525:Medroxyprogesterone; C017296:estrone sulfate