Suspending hormone therapy before mammography not beneficial

Although slight reductions in breast density were observed, briefly suspending hormone therapy prior to screening mammograms did not improve mammography recall rates.

Researchers enrolled 1,704 women aged 45 to 80 years who were due for screening mammograms and who used hormone therapy. Women were randomly assigned to a one-month suspension of hormone therapy (n=570), a two-month suspension (n=567) or no suspension/continuation of hormone therapy (n=567). A blinded, expert radiologist reviewed the mammograms.

After randomization, 13.4% of women withdrew from the study; most withdrew because they declined to discontinue hormone therapy.

Overall, 11.2% of women were recalled for mammograms. The one-month suspension group had the highest rate of recall at 12.3%. The no suspension group had an 11.3% recall rate, and the two-month suspension group had a 9.8% recall rate (P=.45).

Most recalls occurred due to work-up of a probably benign lesion (84.1%). Other reasons included technical issues (7.3%) and work-up of a possible malignant lesion (6.1%). Recall patterns varied by hormone therapy, although several of these findings were statistically nonsignificant.

The researchers observed reductions in the percentage of breast density and dense area for women in the suspension groups. Breast density changed by –0.9% in the one-month suspension group and by –1.5% in the two-month suspension group.

Among women who used estrogen plus progestin, the percentage of breast density reduced by –1.3% in the one-month suspension group and by –2.2% in the two-month suspension group. Researchers observed no change (0.6%) in the no suspension group.

Women assigned to estrogen or estrogen plus progestin who suspended hormone therapy experienced increased symptoms of menopause. Eight serious adverse events occurred during the study, including myocardial infarction, stroke and death. – by Christen Haigh

Buist DSM. Ann Intern Med. 2009;150:752-765.

These researchers show that suspending hormone therapy for two months prior to screening mammography can decrease breast density but does not influence recall rates in a statistically significant way. These data confirm the effects of hormone therapy on mammographic density, but it is likely that longer periods of suspension would be needed to affect recall rate. It is notable that 61% of eligible participants declined participation, and of those that participated in the study, suspension of hormone therapy enhanced menopausal symptoms. Thus, it seems unlikely that suspension of hormone therapy prior to mammography could be a practical way to improve the performance of mammographic screening.

– Douglas Yee, MD

HemOnc Today Editorial Board member