title: The effect of low dose hormone therapy on mammographic breast density.
abstract: OBJECTIVE
  To evaluate the effect of two standard and one low dose continuous hormone therapy regimens on mammography.
  
  
  METHODS
  One hundred and thirty-two non-hysterectomized postmenopausal women were randomly allocated either to conjugated equine estrogens 0.625 mg plus medroxyprogesterone acetate 5 mg (CEE/MPA, n=38), 17beta-estradiol 2 mg plus norethisterone acetate 1 mg (E2/NETA, n=44) or 17beta-estradiol 1 mg plus norethisterone acetate 0.5 mg (low E2/NETA, n=50). Treatment was continuous and the study period lasted 12 months. Main outcome measures were the changes according to Wolfe classification between baseline and 12-month mammograms.
  
  
  RESULTS
  Five (13.2%) women in the CEE/MPA group showed an increase in breast density. Fourteen (31.8%) women on E2/NETA and 6 (12.2%) on low E2/NETA treatment revealed an increase in breast density. No woman exhibited an involution of fibroglandular tissue.
  
  
  CONCLUSIONS
  Different hormone therapy regimens have a variable impact on breast density probably depending on the steroid used. Low dose hormone therapy associates with significantly lesser increase in breast density.
authors.affiliation: 2nd Department of Obstetrics and Gynecology, University of Athens, Aretaieion Hospital, 27, Themistokleous Street, Dionysos, GR-14578 Athens, Greece.
authors.forename: George E
authors.initials: GE
authors.lastname: Christodoulakos
authors.forename: Irene V
authors.initials: IV
authors.lastname: Lambrinoudaki
authors.forename: Athina D
authors.initials: AD
authors.lastname: Vourtsi
authors.forename: Sofia
authors.initials: S
authors.lastname: Vlachou
authors.forename: Maria
authors.initials: M
authors.lastname: Creatsa
authors.forename: Konstantinos P C
authors.initials: KP
authors.lastname: Panoulis
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Botsis
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000187:drug effects*; D003271:Contraceptive Agents, Female / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000008:administration & dosage; D015914:Estrogen Replacement Therapy / Q000379:methods*; D004967:Estrogens / Q000008:administration & dosage; D004966:Estrogens, Conjugated (USP) / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008327:Mammography; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage; D008875:Middle Aged; D009640:Norethindrone / Q000008:administration & dosage / Q000031:analogs & derivatives; D000077563:Norethindrone Acetate; D017698:Postmenopause
chemical_list: D003271:Contraceptive Agents, Female; D004967:Estrogens; D004966:Estrogens, Conjugated (USP); D004958:Estradiol; D000077563:Norethindrone Acetate; D017258:Medroxyprogesterone Acetate; D009640:Norethindrone