Short-term hormone therapy suspension and mammography recall: a randomized trial.
BACKGROUND
Without population-based evidence, some clinicians recommend short-term suspension of hormone therapy to improve the performance of mammography. Hormone therapy increases breast density, and abnormal screening mammograms are more common among women with denser breasts and among women using hormone therapy.


OBJECTIVE
To test whether 1 to 2 months of hormone therapy suspension before screening mammography decreases additional mammographic imaging (recall) in women age 45 to 80 years.


METHODS
3-group randomized, controlled trial.


METHODS
Integrated health plan in western Washington from 2004 to 2007.


METHODS
1704 women age 45 to 80 years who used hormone therapy at their most recent screening (index) mammography, were due for screening (study) mammography, and were still using hormone therapy.


METHODS
Block random assignment (by breast density and hormone therapy type) to no hormone therapy suspension (n = 567) or suspension for 1 month (n = 570) or 2 months (n = 567) before study mammography. One blinded expert radiologist interpreted all mammograms.


METHODS
Recall was the primary outcome, and change in mammographic breast density (percentage and dense area) between the index and study mammograms was the secondary outcome.


RESULTS
Mammography recall rates were 11.3% (61 of 542 women in the no-suspension group), 12.3% (50 of 478 women in the 1-month suspension group), and 9.8% (44 of 451 women in the 2-month suspension group). No subgroups were identified in which brief suspension of hormone therapy resulted in decreased mammography recall. With suspension, decreases in percentage of breast density were orderly and statistically significant: 0.1% (no-suspension group), -0.9% (1-month suspension group), and -1.5% (2-month suspension group). Similar ordered decreases were observed for dense area. Women in the suspension groups experienced increased menopause symptoms.


CONCLUSIONS
Results can only be generalized to women age 45 to 80 years who have used hormone therapy for at least 1 year and will consider short-term suspension; most eligible women (61%) declined participation. Mammography recall was determined by 1 expert radiologist.


CONCLUSIONS
Brief hormone therapy suspension was associated with small changes in breast density and did not affect recall rates. No evidence supports short-term hormone therapy suspension before mammography.
Buist
Diana S M
DS
Group Health Center for Health Studies, University of Washington, and Group Health Permanente, 125 16th Avenue East, Seattle, WA 98112, USA. buist.d@ghc.org
Anderson
Melissa L
ML
Reed
Susan D
SD
Aiello Bowles
Erin J
EJ
Fitzgibbons
E Dawn
ED
Gandara
Juleann C
JC
Seger
Deborah
D
Newton
Katherine M
KM
D000368:Aged; D000369:Aged, 80 and over; D001940:Breast / Q000033:anatomy & histology*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000517:prevention & control; D015914:Estrogen Replacement Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008327:Mammography / Q000592:standards* / Q000706:statistics & numerical data; D008875:Middle Aged; D017698:Postmenopause / Q000502:physiology; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D028761:Withholding Treatment