Differential impact of conventional and low-dose oral hormone therapy, tibolone and raloxifene on mammographic breast density, assessed by an automated quantitative method.
OBJECTIVE
To evaluate impact of different postmenopausal hormone therapy (HT) regimens and raloxifene on mammographic breast density.


METHODS
Open, randomised, comparative clinical trial.


METHODS
Women were recruited through local newspapers and posters. They were examined at the Departments of Haematology, Gynaecology, and Radiology in a University Hospital.


METHODS
A total of 202 healthy postmenopausal women between the age of 45 and 65 years.


METHODS
Women were randomly assigned to receive daily treatment for 12 weeks with tablets containing low-dose HT containing 1 mg 17 beta-estradiol + 0.5 mg norethisterone acetate (NETA) (n = 50), conventional-dose HT containing 2 mg 17 beta-estradiol and 1 mg NETA (n = 50), 2.5 mg tibolone (n = 51), or 60 mg raloxifene (n = 51). Mammographic density was determined at baseline and after 12 weeks by an automated technique in full-field digital mammograms.


METHODS
Mammographic density was expressed as volumetric breast density estimations.


RESULTS
Mammographic breast density increased significantly and to a similar degree in both the conventional- and low-dose HT groups. A small reduction in mammographic breast density was seen in the raloxifene group, whereas those allocated to tibolone treatment only showed minor changes.


CONCLUSIONS
Our findings demonstrated a significant difference in impact on mammographic breast density between the regimens. Although these results indicate a differential effect of these regimens on breast tissue, the relation to breast cancer risk remains unresolved.
Eilertsen
A L
AL
Department of Haematology and Faculty Division, Ullevål University Hospital Trust, Oslo, Norway. a.l.eilertsen@medisin.uio.no
Karssemeijer
N
N
Skaane
P
P
Qvigstad
E
E
Sandset
P M
PM
D000284:Administration, Oral; D000368:Aged; D001940:Breast / Q000033:anatomy & histology / Q000187:drug effects*; D003280:Contraceptives, Oral, Synthetic / Q000008:administration & dosage / Q000494:pharmacology; D004338:Drug Combinations; D004958:Estradiol / Q000008:administration & dosage; D020847:Estrogen Receptor Modulators / Q000008:administration & dosage / Q000494:pharmacology; D004967:Estrogens / Q000008:administration & dosage / Q000494:pharmacology; D005260:Female; D020249:Hormone Replacement Therapy / Q000009:adverse effects*; D006801:Humans; D008327:Mammography; D008875:Middle Aged; D009640:Norethindrone / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D000077563:Norethindrone Acetate; D009652:Norpregnenes / Q000008:administration & dosage / Q000494:pharmacology; D009929:Organ Size; D017698:Postmenopause / Q000187:drug effects*; D020849:Raloxifene Hydrochloride / Q000008:administration & dosage / Q000494:pharmacology
D003280:Contraceptives, Oral, Synthetic; D004338:Drug Combinations; D020847:Estrogen Receptor Modulators; D004967:Estrogens; D009652:Norpregnenes; D020849:Raloxifene Hydrochloride; D004958:Estradiol; D000077563:Norethindrone Acetate; C027385:tibolone; D009640:Norethindrone